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Title: Assessing Safety Culture among Personnel in Governmental Construction Sites at Saudi Arabia: A Quantitative Study Approach.
Creator: Alrehaili, Omar, Karwowski, Waldemar, Elshennawy, Ahmad, Hancock, Peter, Mikusinski, Piotr, University of Central Florida
Abstract / Description: Safety is an essential issue for organizations to survive, especially for hazardous industries such as the construction industry. The construction industry is considered to be one of the major industries that help in the growth of the economy and the infrastructure of all countries. Recently, scholars have paid increasing attention to the concept of safety culture due to its role in decreasing the occurrences of accidents and injuries. Safety culture has become the focus of all industries and...
Show moreSafety is an essential issue for organizations to survive, especially for hazardous industries such as the construction industry. The construction industry is considered to be one of the major industries that help in the growth of the economy and the infrastructure of all countries. Recently, scholars have paid increasing attention to the concept of safety culture due to its role in decreasing the occurrences of accidents and injuries. Safety culture has become the focus of all industries and has received much attention in recent years, especially within the construction industry. Absence of this culture is a major cause of injuries and accidents in the construction field. In the construction industry, personnel's perception of safety culture is vital to prevent accidents or behavior misconduct. Also, focusing on personnel's safety culture on construction sites provides an opportunity to decrease risks and unsafe behaviors to improve the overall safety level. Workers' performance and behaviors are shaped by their awareness and view of safety culture inside their work environment. Generally, safety performance in the construction field is still unsatisfactory based on reporting records.The present study observed the influence of safety culture on construction's personnel's safety performance on large governmental construction projects in Saudi Arabia. Construction personnel's safety performance is measured by their attitude toward violations and error behaviors. This research also exams the role of personnel's motivation toward construction safety as a mediating variable between construction safety culture and safety performance constructs, including error and violation behaviors. The research adopted a quantitative method by using a questionnaire for the purpose of data collection and analysis. A total of 434 questionnaires were collected from construction personnel including project managers, engineers, and supervisors through their voluntary participation in this study. Statistical analysis was used to analyze the data collected including descriptive statistics, confirmatory factor analysis (CFA) and structural equation modeling (SEM) techniques. Confirmatory factor analysis is used for validating each factor with its measurable items. Finally, this study applied the concept of structural equation modeling (SEM) to evaluate the correlation between all latent variables in the study's conceptualized model.The outcomes of the study show that safety culture has a direct influence on construction personnel's attitudes toward violations and an indirect effect on construction personnel's error behavior. Furthermore, safety culture has a significant effect on improving safety motivation, as well. Safety motivation for construction safety has a direct effect on errors behaviors. Conversely, safety motivation does not have a mediating effect on construction personnel's attitudes toward violations. Therefore, safety motivation's mediating role was significant only between safety culture and errors behaviors.This research has added to the existing knowledge about the important part of safety culture as a key interpreter of safety performance in construction field. The current study contributes to psychological safety through examining the influence of safety culture as the interpreter for enhancing motivation for construction safety. Additionally, this research evaluated safety culture's influence on construction personnel's attitudes toward violations and construction personnel's error behavior. The outcomes of the study are useful and recommended to be used by construction management to better pinpoint the reasons for unsafe behaviors within the construction industry. The results of this research highlights management's role in determining, and affecting, workers' behaviors.
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Date Issued: 2016
Identifier: CFE0006434, ucf:51470
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006434

Title: Assessing Safety Culture among Pilots in Saudi Airlines: A Quantitative Study Approach.
Creator: Alsowayigh, Mohammad, Karwowski, Waldemar, Elshennawy, Ahmad, Lee, Gene, Hancock, Peter, Mikusinski, Piotr, University of Central Florida
Abstract / Description: In high- risk industries, such as aviation, safety is a key for organization survivor. Most accidents involve human losses and bring substantial cost to organizations. Accidents can devastate the reputation and profitability of any organization. In aviation, more than 80% of aircraft accidents are related to human errors. Safety culture has substantial impact on the success of any organization. Employees' performance and behaviors are influenced by their perception of safety culture within...
Show moreIn high- risk industries, such as aviation, safety is a key for organization survivor. Most accidents involve human losses and bring substantial cost to organizations. Accidents can devastate the reputation and profitability of any organization. In aviation, more than 80% of aircraft accidents are related to human errors. Safety culture has substantial impact on the success of any organization. Employees' performance and behaviors are influenced by their perception of safety culture within their organization. In the aviation industry, pilots are considered the last resort to prevent accidents or mishaps in the air or ground. The focus on pilots' perception of safety culture is vital to understand how the airline can influence pilots' behaviors in the flight deck, and provide opportunities to minimize risk or unsafe behavior in the future. The present study examined the effect of safety culture on safety performance among pilots of Saudi Airlines. Safety performance was measured by pilot attitude toward violations and pilot error behavior. The study further analyzed the mediating role of pilot commitment to the airline between safety culture and measures of safety performance. The study used a quantitative approach using survey questionnaire to collect the data. A total of 247 commercial airline pilots, captain and first officer, flying at Saudi Airlines voluntarily participated in the study. Confirmatory factor analysis was conducted to validate each latent construct. The study used structural equation modeling (SEM) to analyze the relationship between all variables in the study using AMOS 22 software. The study results revealed that safety culture had a direct effect on pilot attitude toward violations and indirect effect on pilot error behavior. Moreover, safety culture had strong effect on enhancing pilot commitment to the airline. The mediating role of pilot commitment to the airline was not significant, and could not mediate the relationship between safety culture and measures of safety performance. The present research contributed to the current state of knowledge about the significant role of safety culture as a main predictor of safety performance in civil aviation. The present study contributes to aviation psychology by analyzing the effect of safety culture as a predictor for improving pilot commitment to the airline. In addition, this research analyzed the effect of safety culture on pilot attitude toward violations and pilot error behavior. Study findings can be used by airline management to better identify causes of unsafe behavior inside the cockpit. The outcomes of this research emphasize the role of management in shaping and affecting employees' behaviors and attitudes.
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Date Issued: 2014
Identifier: CFE0005454, ucf:50371
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005454

Title: COMPARISON OF ARNP AND PHYSICIAN MALPRACTICE IN STATES WITH AND WITHOUT CONTROLLED SUBSTANCE PRESCRIBING AUTHORITY.
Creator: Chandler, Deborah, Rash, Elizabeth, University of Central Florida
Abstract / Description: Florida is one of two states that do not allow ARNPs to prescribe controlled substances. The Florida Legislature has expressed concern regarding the safety of ARNPs prescribing controlled substances. The purpose of this study was to compare malpractice rates of ARNPs and physicians in states with and without controlled substance prescribing. The design was a direct comparison of malpractice rates in states with and without ARNP controlled substance prescriptive authority. Comparison of...
Show moreFlorida is one of two states that do not allow ARNPs to prescribe controlled substances. The Florida Legislature has expressed concern regarding the safety of ARNPs prescribing controlled substances. The purpose of this study was to compare malpractice rates of ARNPs and physicians in states with and without controlled substance prescribing. The design was a direct comparison of malpractice rates in states with and without ARNP controlled substance prescriptive authority. Comparison of malpractice claims was made between physicians (MDs and DOs collectively) and ARNPs in the United States and by state ARNP prescribing authority. Comparison of malpractice claims was also made between Florida and states that were demographically similar. The results showed that ARNPs have significantly less malpractice than physicians in the United States. In addition, there were no significant differences in malpractice, whether or not the ARNP was allowed to prescribe controlled substances. Finally, ARNPs working in states that are demographically similar to Florida, but allowed to prescribe controlled substances had no significant increase in malpractice. This study showed that there is no increase in malpractice rates in states where ARNPs prescribe controlled substances, either fully or partially, supporting the hypothesis.
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Date Issued: 2010
Identifier: CFE0003212, ucf:48588
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003212

Title: System safety in rail transportation.
Creator: Smith, Quave Norvell, null, null, Engineering
Abstract / Description: Florida Technological University College of Engineering Thesis; This thesis, "System Safety in Rail Transportation" is addressed to an individual having a basic technical background but little or no experience in this field. The thesis discusses the need for and the benefits to be obtained by using system safety techniques and principles in the railroad industry. Examples of typical railroad accidents are reviewed, and it is pointed out that analysis of the hazards in the railroad industry...
Show moreFlorida Technological University College of Engineering Thesis; This thesis, "System Safety in Rail Transportation" is addressed to an individual having a basic technical background but little or no experience in this field. The thesis discusses the need for and the benefits to be obtained by using system safety techniques and principles in the railroad industry. Examples of typical railroad accidents are reviewed, and it is pointed out that analysis of the hazards in the railroad industry prior to the accidents would have identified problems which eventually resulted in the accidents. The system safety approach, which was developed for use in the aerospace and aviation fields, has proved to be extremely effective and is now being adapted to many other areas. The surface modes of transportation have the greatest need for these techniques. The techniques covered in this thesis include Hazard Analysis, Fault or Logic Tree Analysis, Failure Modes and Effects Analysis, and Probabilistic Cost Analysis. The thesis also describes a hypothetical model for organizing and implementing system safety approaches in an existing railroad company.
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Date Issued: 1976
Identifier: CFR0003512, ucf:53012
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0003512

Title: Impact of Dynamic Message Signs on Driver Behavior Under Reduced Visibility Conditions.
Creator: Selby, Ryan, Abdel-Aty, Mohamed, Eluru, Naveen, Lee, JaeYoung, University of Central Florida
Abstract / Description: Fog along roadways is a dangerous hazard that leads to crashes resulting from limited visibility. Low visibility gives drivers less time to react to potential obstacles that can suddenly appear and require immediate action. To solve this issue, early warning systems involving Dynamic Message Signs or other types of devices are used to alert drivers of the impending visibility condition so that they are prepared. This research focuses on testing the effectiveness of one form of warning systems...
Show moreFog along roadways is a dangerous hazard that leads to crashes resulting from limited visibility. Low visibility gives drivers less time to react to potential obstacles that can suddenly appear and require immediate action. To solve this issue, early warning systems involving Dynamic Message Signs or other types of devices are used to alert drivers of the impending visibility condition so that they are prepared. This research focuses on testing the effectiveness of one form of warning systems to investigate how it impacts driver behavior in foggy conditions. To accomplish this objective, a simulation study is developed to test variables of interest including: Roadway Type, Fog Level, DMS Presence, Beacon Presence, Traffic Volume, and DMS Message Provided. Using a factorial design, 24 scenarios are created by randomizing the variables listed using statistical software to be tested on 72 volunteer participants. Using a NADS MiniSim Driving Simulator, the participants driving behavior is recorded including speed and breaking behavior under an initial clear condition followed by a reduced visibility fog condition. From demographics, drivers age 35 and over consistently showed a higher likelihood of speed reduction between clear and fog conditions with overall reduction increasing with age. This is seen when looking at the mean change in speed based on driver age where young drivers (18-25 yrs) reduced speeds by 7MPH, older drivers (35-45 yrs) reduced by 12MPH, and elder drivers (65+ yrs) reduced by 17MPH. The more often a person drove and those that were educated at a graduate level also showed a higher chance of speed reductions. This demonstrates the impact of experience and exposure to driving performance under reduced visibility conditions. Those who recently drove under fog conditions or learned to drive in Florida were found to be less likely to reduce their speeds when entering the fog. This is attributed to these drivers being confident or familiar with the environment resulting in risky driving behavior. For the scenario variables, it is determined that the type of roadway a driver travels plays a major role in how much speed reduction occurs and thus how much a driver decelerates when entering a low visibility environment. On average, drivers traversed the fog zone at 50MPH with the lowest travel speed being 30MPH. Since the speed limit on the freeway is 5MPH higher than the arterial, drivers' traveling along this road are noted to decelerate at higher rates to achieve this target speed. Additionally, DMS presence and message also provided an impact on the drivers' choice to decelerate and reduce travel speed within the fog condition. Under the most severe conditions, the probability of a driver reducing speed increases as the number of DMS present increases. Additionally, when a DMS presents a warning and specifies the action that a driver should take, in this case 'reduce speed,' greater speed reductions and decelerations are observed and are more likely to occur. Interestingly the number of DMS did not have a significant impact on driver behavior under every fog condition like the message presented did except in the most severe fog condition. Taking into account that 33% of drivers did not accurately remember the number of DMS encountered it can be concluded that the warning message itself is the most important aspect of the early warning system. This indicates that drivers accurately remember being directed to reduce speed whether they are given the advisement once or multiple times based on the number of DMS present. Further research into how the warning message is presented or worded could provide additional insight into the impact it can have on driver behavior. Since it is observed that drivers acknowledge the 'reduce speed' advisement, it is likely that specifying a specific speed limit could also warrant driver obedience. Additional testing and observation of driver reaction to larger traffic volumes and situations within the fog would also allow for further analysis of driver behavior under reduced visibility and the impact the early warning system has on their behavior.
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Date Issued: 2016
Identifier: CFE0006179, ucf:51116
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006179

Title: Joint modeling of traffic related crashes: a Copula based approch.
Creator: Nashad, Tammam, Eluru, Naveen, Abdel-Aty, Mohamed, Radwan, Essam, University of Central Florida
Abstract / Description: The study contributes to safety literature on transportation safety by employing copula based models for count frequency analysis at a macro-level. Most studies in the transportation safety area identify a single count variable (such as vehicular, pedestrian or bicycle crash counts) for a spatial unit and study the impact of exogenous variables. While the traditional count models perform adequately in the presence of a single count variable, it is necessary to modify these approaches to...
Show moreThe study contributes to safety literature on transportation safety by employing copula based models for count frequency analysis at a macro-level. Most studies in the transportation safety area identify a single count variable (such as vehicular, pedestrian or bicycle crash counts) for a spatial unit and study the impact of exogenous variables. While the traditional count models perform adequately in the presence of a single count variable, it is necessary to modify these approaches to examine multiple dependent variables for each study unit. To that extent, the current research effort contributes to literature by developing two multivariate models based on copula methodology. First, a copula based bivariate negative binomial model for pedestrian and bicyclist crash frequency analysis is developed. Second, a multivariate negative binomial model for crashes involving non-motorized road users, passenger cars, vans, light trucks and heavy trucks is proposed. The proposed approaches also accommodate for potential heterogeneity (across zones) in the dependency structure. The formulated models are estimated using traffic crash count data at the Statewide Traffic Analysis Zone (STAZ) level for the state of Florida for the years 2010 through 2012. The STAZ level variables considered in our analysis include exposure measures, socio-economic characteristics, road network characteristics and land use attributes. A policy analysis is also conducted along with a representation of hotspot identification to illustrate the applicability of the proposed model for planning purposes. The development of such spatial profiles will allow planners to identify high risk zones for screening and treatment purposes.
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Date Issued: 2016
Identifier: CFE0006153, ucf:51124
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006153

Title: DOES SAFETY CULTURE PREDICT CLINICAL OUTCOMES?.
Creator: Wilson, Katherine, Salas, Eduardo, University of Central Florida
Abstract / Description: Patient safety in healthcare has become a national objective. Healthcare organizations are striving to improve patient safety and have turned to high reliability organizations as those in which to model. One initiative taken on by healthcare is improving patient safety culture--shifting from one of a 'no harm, no foul' to a culture of learning that encourages the reporting of errors, even those in which patient harm does not occur. Lacking from the literature, however, is an...
Show morePatient safety in healthcare has become a national objective. Healthcare organizations are striving to improve patient safety and have turned to high reliability organizations as those in which to model. One initiative taken on by healthcare is improving patient safety culture--shifting from one of a 'no harm, no foul' to a culture of learning that encourages the reporting of errors, even those in which patient harm does not occur. Lacking from the literature, however, is an understanding of how safety culture impacts outcomes. While there has been some research done in this area, and safety culture is argued to have an impact, the findings are not very diagnostic. In other words, safety culture has been studied such that an overall safety culture rating is provided and it is shown that a positive safety culture improves outcomes. However, this method does little to tell an organization what aspects of safety culture impact outcomes. Therefore, this dissertation sought to answer that question but analyzing safety culture from multiple dimensions. The results found as a part of this effort support previous work in other domains suggesting that hospital management and supervisor support does lead to improved perceptions of safety. The link between this support and outcomes, such as incidents and incident reporting, is more difficult to determine. The data suggests that employees are willing to report errors when they occur, but the low occurrence of such reportable events in healthcare precludes them from doing so. When a closer look was taken at the type of incidents that were reported, a positive relationship was found between support for patient safety and medication incidents. These results initially seem counterintuitive. To suggest a positive relationship between safety culture and medication incidents on the surface detracts from the research in other domains suggesting the opposite. It could be the case that an increase in incidents leads an organization to implement additional patient safety efforts, and therefore employees perceive a more positive safety culture. Clearly more research is needed in this area. Suggestions for future research and practical implications of this study are provided.
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Date Issued: 2007
Identifier: CFE0001924, ucf:47472
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001924

Title: The Role of Resilience on Second-Victim Outcomes: Examining Individual and External Factors of Medical Professionals.
Creator: Hernandez, Claudia, Burke, Shawn, Bowers, Clint, Porter, Marissa, University of Central Florida
Abstract / Description: The present work is intended to bring awareness to medical professionals impacted by the occurrence of errors they have committed or witnessed (i.e., second-victims) and highlight the negative effects that may result from such errors. The purpose of this research is to test whether resilience and negative affect that is experienced after a medical error are related. Additionally, four variables are tested as moderators of this relationship, two of which are considered individual variables (i...
Show moreThe present work is intended to bring awareness to medical professionals impacted by the occurrence of errors they have committed or witnessed (i.e., second-victims) and highlight the negative effects that may result from such errors. The purpose of this research is to test whether resilience and negative affect that is experienced after a medical error are related. Additionally, four variables are tested as moderators of this relationship, two of which are considered individual variables (i.e., self-efficacy and work meaningfulness), and two of which are characterized as external variables (i.e., co-worker support and organizational support). Twenty-two healthcare professionals from a hospital's Cardio-Vascular Intensive Care Unit participated in a short survey. Results showed a relationship exists between resilience and negative affect experienced by second victims, post-error. The limitations of the current work, practical implications, and ideas for future research will be expanded upon herein.
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Date Issued: 2019
Identifier: CFE0007651, ucf:52475
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007651

Title: Macroscopic Crash Analysis and Its Implications for Transportation Safety Planning.
Creator: Siddiqui, Chowdhury, Abdel-Aty, Mohamed, Abdel-Aty, Mohamed, Uddin, Nizam, Huang, Helai, University of Central Florida
Abstract / Description: Incorporating safety into the transportation planning stage, which is often termed as transportation safety planning (TSP), relies on the vital interplay between zone characteristics and zonal traffic crashes. Although a few safety studies had made some effort towards integrating safety and planning, several unresolved problems and a complete framework of TSP are still absent in the literature. This research aims at examining the suitability of the current traffic-related zoning planning...
Show moreIncorporating safety into the transportation planning stage, which is often termed as transportation safety planning (TSP), relies on the vital interplay between zone characteristics and zonal traffic crashes. Although a few safety studies had made some effort towards integrating safety and planning, several unresolved problems and a complete framework of TSP are still absent in the literature. This research aims at examining the suitability of the current traffic-related zoning planning process in a new suggested planning method which incorporates safety measures. In order to accomplish this broader research goal, the study defined its research objectives in the following directions towards establishing a framework of TSP- i) exploring the existing key determinants in traditional transportation planning (e.g., trip generation/distribution data, land use types, demographics, etc.) in order to develop an effective and efficient TSP framework, ii) investigation of the Modifiable Aerial Unit Problem (MAUP) in the context of macro-level crash modeling to investigate the effect of the zone's size and boundary, iii) understanding neighborhood influence of the crashes at or near zonal boundaries, and iv) development of crash-specific safety measure in the four-step transportation planning process.This research was conducted using spatial data from the counties of West Central Florida. Analysis of different crash data per spatial unit was performed using nonparametric approaches (e.g., data mining and random forest), classical statistical methods (e.g., negative binomial models), and Bayesian statistical techniques. In addition, a comprehensive Geographic Information System (GIS) based application tools were utilized for spatial data analysis and representation.Exploring the significant variables related to specific types of crashes is vital in the planning stages of a transportation network. This study identified and examined important variables associated with total crashes and severe crashes per traffic analysis zone (TAZ) by applying nonparametric statistical techniques using different trip related variables and road-traffic related factors. Since a macro-level analysis, by definition, will necessarily involve aggregating crashes per spatial unit, a spatial dependence or autocorrelation may arise if a particular variable of a geographic region is affected by the same variable of the neighboring regions. So far, few safety studies were performed to examine crashes at TAZs and none of them explicitly considered spatial effect of crashes occurring in them. In order to understand the clear picture of spatial autocorrelation of crashes, this study investigated the effect of spatial autocorrelation in modeling pedestrian and bicycle crashes in TAZs. Additionally, this study examined pedestrian crashes at Environmental Justice (EJ) TAZs which were identified in compliance with the various ongoing practices undertaken by Metropolitan Planning Organizations (MPOs) and previous research. Minority population and the low-income group are two important criteria based on which EJ areas are being identified. These unique areal characteristics have been of particular interest to the traffic safety analysts in order to investigate the contributing factors of pedestrian crashes in these deprived areas. Pedestrian and bicycle crashes were estimated as a function of variables related to roadway characteristics, and various demographic and socio-economic factors. It was found that significant differences are present between the predictor sets for pedestrian and bicycle crashes. In all cases the models with spatial correlation performed better than the models that did not account for spatial correlation among TAZs. This finding implied that spatial correlation should be considered while modeling pedestrian and bicycle crashes at the aggregate or macro-level. Also, the significance of spatial autocorrelation was later found in the total and severe crash analyses and accounted for in their respective modeling techniques.Since the study found affirmative evidence about the inclusion of spatial autocorrelation in the safety performance functions, this research considered identifying appropriate spatial entity based on which TSP framework would be developed. A wide array of spatial units has been explored in macro-level crash modeling in previous safety research. With the advancement of GIS, safety analysts are able to analyze crashes for various geographical units. However, a clear guideline on which geographic entity should a modeler choose is not present so far. This preference of spatial unit can vary with the dependent variable of the model. Or, for a specific dependent variable, models may be invariant to multiple spatial units by producing a similar goodness-of-fits. This problem is closely related to the Modifiable Areal Unit Problem which is a common issue in spatial data analysis. The study investigated three different crash (total, severe, and pedestrian) models developed for TAZs, block groups (BGs) and census tracts (CTs) using various roadway characteristics and census variables (e.g., land use, socio-economic, etc.); and compared them based on multiple goodness-of-fit measures.Based on MAD and MSPE it was evident that the total, severe and pedestrian crash models for TAZs and BGs had similar fits, and better than the ones developed for CTs. This indicated that the total, severe and pedestrian crash models are being affected by the size of the spatial units rather than their zoning configurations. So far, TAZs have been the base spatial units of analyses for developing travel demand models. Metropolitan planning organizations widely use TAZs in developing their long range transportation plans (LRTPs). Therefore, considering the practical application it was concluded that as a geographical unit, TAZs had a relative ascendancy over block group and census tract.Once TAZs were selected as the base spatial unit of the TSP framework, careful inspections on the TAZ delineations were performed. Traffic analysis zones are often delineated by the existing street network. This may result in considerable number of crashes on or near zonal boundaries. While the traditional macro-level crash modeling approach assigns zonal attributes to all crashes that occur within the zonal boundary, this research acknowledged the inaccuracy resulting from relating crashes on or near the boundary of the zone to merely the attributes of that zone. A novel approach was proposed to account for the spatial influence of the neighboring zones on crashes which specifically occur on or near the zonal boundaries. Predictive model for pedestrian crashes per zone were developed using a hierarchical Bayesian framework and utilized separate predictor sets for boundary and interior (non-boundary) crashes. It was found that these models (that account for boundary and interior crashes separately) had better goodness-of-fit measures compared to the models which had no specific consideration for crashes located at/near the zone boundaries. Additionally, the models were able to capture some unique predictors associated explicitly with interior and boundary-related crashes. For example, the variables- 'total roadway length with 35mph posted speed limit' and 'long term parking cost' were statistically not significantly different from zero in the interior crash model but they were significantly different from zero at the 95% level in the boundary crash model.Although an adjacent traffic analysis zones (a single layer) were defined for pedestrian crashes and boundary pedestrian crashes were modeled based on the characteristic factors of these adjacent zones, this was not considered reasonable for bicycle-related crashes as the average roaming area of bicyclists are usually greater than that of pedestrians. For smaller TAZs sometimes it is possible for a bicyclist to cross the entire TAZ. To account for this greater area of coverage, boundary bicycle crashes were modeled based on two layers of adjacent zones. As observed from the goodness-of-fit measures, performances of model considering single layer variables and model considering two layer variables were superior from the models that did not consider layering at all; but these models were comparable. Motor vehicle crashes (total and severe crashes) were classified as 'on-system' and 'off-system' crashes and two sub-models were fitted in order to calibrate the safety performance function for these crashes. On-system and off-system roads refer to two different roadway hierarchies. On-system or state maintained roads typically possess higher speed limit and carries traffic from distant TAZs. Off-system roads are, however, mostly local roads with relatively low speed limits. Due to these distinct characteristics, on-system crashes were modeled with only population and total employment variables of a zone in addition to the roadway and traffic variables; and all other zonal variables were disregarded. For off-system crashes, on contrary, all zonal variables was considered. It was evident by comparing this on- and off-system sub-model-framework to the other candidate models that it provided superior goodness-of-fit for both total and severe crashes.Based on the safety performance functions developed for pedestrian, bicycle, total and severe crashes, the study proposed a novel and complete framework for assessing safety (of these crash types) simultaneously in parallel with the four-step transportation planning process with no need of any additional data requirements from the practitioners' side.
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Date Issued: 2012
Identifier: CFE0004191, ucf:49009
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004191

Title: Analysis of pedestrian safety using micro-simulation and driving simulator.
Creator: Wu, Jiawei, Radwan, Essam, Abdel-Aty, Mohamed, Abou-Senna, Hatem, University of Central Florida
Abstract / Description: In recent years, traffic agencies have begun to place emphasis on the importance of pedestrian safety. In the United States, nearly 70,000 pedestrians were reported injured in 2015. Although the number only account for 3% of all the people injured in traffic crashes, the number of pedestrian fatalities is still around 15% of total traffic fatalities. Furthermore, the state of Florida has consistently ranked as one of the worst states in terms of pedestrian crashes, injuries and fatalities....
Show moreIn recent years, traffic agencies have begun to place emphasis on the importance of pedestrian safety. In the United States, nearly 70,000 pedestrians were reported injured in 2015. Although the number only account for 3% of all the people injured in traffic crashes, the number of pedestrian fatalities is still around 15% of total traffic fatalities. Furthermore, the state of Florida has consistently ranked as one of the worst states in terms of pedestrian crashes, injuries and fatalities. Therefore, it is befitting to focus on the pedestrian safety. This dissertation mainly focused on pedestrian safety at both midblock crossings and intersections by using micro-simulation and driving simulator. First, this study examined if the micro-simulation models (VISSIM and SSAM) could estimate pedestrian-vehicle conflicts at signalized intersections. A total of 42 video-hours were recorded at seven signalized intersections for field data collection. The observed conflicts from the field were used to calibrate VISSIM and replicate the conflicts. The calibrated and validated VISSIM model generated the pedestrian-vehicle conflicts from SSAM software using the vehicle trajectory data in VISSIM. The mean absolute percent error (MAPE) was used to determine the optimum TTC and PET thresholds for pedestrian-vehicle conflicts and linear regression analysis was used to study the correlation between the observed and simulated conflicts at the established thresholds. The results indicated the highest correlation between the simulated and observed conflicts when the TTC parameter was set at 2.7 and the PET was set at 8. Second, the driving simulator experiment was designed to assess pedestrian safety under different potential risk factors at both midblock crossings and intersections. Four potential risk factors were selected and 67 subjects participated in this experiment. In order to analyze pedestrian safety, the surrogate safety measures were examined to evaluate these pedestrian-vehicle conflicts. Third, by using the driving simulator data from the midblock crossing scenario, typical examples of drivers' deceleration rate and the distance to crosswalk were summarized, which exhibited a clear drivers' avoidance pattern during the vehicle pedestrian conflicts. This pattern was summarized into four stages, including the brake response stage, the deceleration adjustment stage, the maximum deceleration stage, and the brake release stage. In addition, the pedestrian-vehicle conflict prediction model was built to predict the minimum distance between vehicle and pedestrian.Finally, this study summarized the three different kinds of data that were to evaluate the pedestrian safety, including field data, simulation data, and driving simulator data. The process of combining of field data, simulation data, and simulator data was proposed. The process would show how the researches could evaluate the pedestrian safety by using the field observations, micro-simulation, and driving simulator.
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Date Issued: 2017
Identifier: CFE0006822, ucf:51770
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006822

Title: A CONFIGURAL APPROACH TO PATIENT SAFETY CLIMATE: THE RELATIONSHIP BETWEEN CLIMATE PROFILE CHARACTERISTICS AND PATIENT OUTCOMES.
Creator: Weaver, Sallie, Salas, Eduardo, University of Central Florida
Abstract / Description: Patient safety climate is defined as a holistic snapshot of enacted work environment practices and procedures related to patient safety, derived from shared perceptions of social and environmental work characteristics. While patient safety climate has been touted as a critical factor underlying safe patient care, our understanding of input factors influencing shared climate perceptions and, in turn, the effects of climate as a collective, group-level construct on important outcomes remains...
Show morePatient safety climate is defined as a holistic snapshot of enacted work environment practices and procedures related to patient safety, derived from shared perceptions of social and environmental work characteristics. While patient safety climate has been touted as a critical factor underlying safe patient care, our understanding of input factors influencing shared climate perceptions and, in turn, the effects of climate as a collective, group-level construct on important outcomes remains underdeveloped, both theoretically and empirically. Therefore, the current study examines (1) the antecedents that impact individual patient safety climate perceptions and (2) the relationships between hospital unit patient safety climate and two important unit level outcomes: patient willingness to recommend a facility to others and patient safety. This study also examines climate strength-the degree to which climate perceptions are shared-as a moderator of these relationships. While climate is conceptualized as a holistic description of the working environment, existing evidence has focused on relationships between the independent dimensions of patient safety climate and patient safety. No study to date has examined the configurations (i.e. patterns or profiles) among the multiple dimensions of patient safety climate or how these configurations are related to important employee and patient outcomes. This gap is redressed in the current study by examining patient safety climate in terms of three profile characteristics: (1) climate elevation (i.e., mean positive or negative valence across all dimensions), (2) climate variability (i.e., variance among dimensions), and (3) climate shape (i.e., the pattern of peaks and valleys among climate dimensions). Evidence from studies of general organizational climate suggests that the shape of the pattern among climate dimensions, the overall mean score across dimensions, and the degree to which dimension scores vary are predictive of employee attitudes, customer satisfaction, and organizational financial performance (Dickson et al., 2006; Joyce & Slocum, 1984; Jackofsky & Slocum, 1988; Gonzalez-Roma, Peiro, & Zornoza, 1999; Litwin & Stringer, 1968; Schulte et al., 2009). The current study, then, tests a theoretical model of patient safety climate examining the configural nature of the construct. An archival dataset collected from seven hospitals located in a metropolitan area of the southeastern United States was utilized to test study hypotheses. Data was collected from 3,149 individuals nested within 84 hospital units using the Hospital Survey on Patient Safety Culture (Sorra & Nieva, 2004). Unit level patient safety and patient willingness to recommend was collected by the hospital risk management and nursing administration departments. Hierarchical linear modeling (HLM7; Raudenbush, Bryk, Cheong, Congdon, & du Toit, 2011) was utilized to test hypotheses regarding antecedents of individual level perceptions of patient safety climate to account for the fact that individuals were nested within hospital units. Traditional multiple regression analyses were utilized to test unit level hypotheses examining the relationships between unit level patient safety climate and patient outcomes. Results indicated that unit membership was significantly related to individual climate perceptions-specifically, individual-level climate profile elevation. In turn, individual climate profile elevation and profile variability were related to employee willingness to recommend their organization to family and friends in need of care. At the unit level of analysis, climate profile variability was significantly related to patient willingness to recommend the organization to others, and climate shape was found to be related to patient safety. Furthermore, these results were not dependent on climate strength. The current study meaningfully contributes to the conceptual understanding of the patient safety climate construct by examining the degree to which configural aspects of the construct are predictive of important outcomes across multiple levels of analysis. In this way, it extends beyond existing studies of climate configurations to examine relationships at multiple levels of analysis and to also examine the moderating effects of climate strength. Practically, results provide insight into how the construct of patient safety climate can be used diagnostically and prescriptively to improve patient care and the working environment for providers. In addition to contributing to the theoretical understanding of the patient safety climate construct, this study also augments the evidence-base available to administrators, front-line providers, and regulators regarding how patient safety climate can be used to guide and align quality improvement efforts for greatest impact.
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Date Issued: 2011
Identifier: CFE0003992, ucf:48668
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003992

Title: ORGANIZATIONAL SAFETY CULTURE AND IDIVIDUAL SAFETY BEHAVIOR: A CASE STUDY OF THE TURKISH NATIONAL POLICE AVIATION DEPARTMENT.
Creator: Uryan, Yildirim, T. H. Wan, Thomas, University of Central Florida
Abstract / Description: Human related accidents in high-risk industries amount to a significant economic hazard and incur tremendous damages, causing excessive operational costs and loss of life. The aviation industry now observes human-related accidents more frequently than in the past, an upswing attributable to cutting-edge technology usage and the complex systems employed by aviation organizations. Historically, aviation accidents have been attributed to individual unsafe behavior. However, contemporary accident...
Show moreHuman related accidents in high-risk industries amount to a significant economic hazard and incur tremendous damages, causing excessive operational costs and loss of life. The aviation industry now observes human-related accidents more frequently than in the past, an upswing attributable to cutting-edge technology usage and the complex systems employed by aviation organizations. Historically, aviation accidents have been attributed to individual unsafe behavior. However, contemporary accident causation models suggest that organizational-level factors influence individual safety performance, as human-related accidents take place in an organizational context. The present study examines the formation of organizational safety culture and influence on individualsÃ‚Â' safety behavior in a police aviation environment. The theory of planned behavior guides the study model in explaining individual variability in safety behavior via organizational safety culture. The study conceptualized organizational safety culture and individual safety behavior as multidimensional constructs. Confirmatory factor analysis was conducted for each latent construct to validate the construct validity for each measurement model. Organizational safety culture was observed via safety climate facets, which contained four subcomponents including individual attitude, group norms, management attitude, and workplace pressures. Individual safety behavior contained violation and error components observed by self-reported statements. Structural equation modeling was conducted to test the study hypotheses. Utilizing a sample of 210 employees from the Turkish National Police Aviation Department, a 53-item survey was conducted to measure individualsÃ‚Â' safety culture perceptions and self-reported safety behaviors. The results suggest that individual safety behavior is significantly influenced by organizational safety culture. Except for the relation between workplace pressures and intention, all suggested relations and correlations were statistically significant. The four-factor measurement model of organizational safety climate fit reasonably well to the data, and most correlations between the safety climate components were significant at the .05 level. IndividualsÃ‚Â' self-reported error behavior is positively associated with age, and individualsÃ‚Â' self-reported violation behavior is positively associated with years of service. Overall, along with organizational safety culture, age and service-year variables accounted for 65% of the variance in intention, 55% of the variance in violation behavior, and 68% of the variance in error behavior. Lastly, no significant difference manifested among pilots, maintenance personnel, and office staff according to their self-related safety behaviors. The findings have theoretical, policy, and managerial implications. First, the theory of planned behavior was tested, and its usefulness in explaining individualsÃ‚Â' safety behavior was demonstrated. The survey instrument of the study, and multi-dimensional measurement models for organizational safety climate and individual safety behavior were theoretical contributions of the study. Second, the emergence of informal organizational structures and their effects on individuals indicated several policy implications. The study also revealed the importance of informal structures in organizations performing in high-risk environments, especially in designing safety systems, safety policies, and regulations. Policy modification was suggested to overcome anticipated obstacles and the perceived difficulty of working with safety procedures. The influences of age on error behavior and years of service on violation behavior point to the need for several policy modifications regarding task assignment, personnel recruitment, health reports, and violation assessment policies. As well, managerial implications were suggested, including changing individualsÃ‚Â' perceptions of management and group attitudes toward safety. The negative influence of anticipated obstacles and the perceived difficulties of safety procedures on individual safety behavior pointed out managementÃ‚Â's role in reducing risks and accidents by designing intervention programs to improve safety performance, and formulating proactive solutions for problems typically leading to accidents and injuries.
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Date Issued: 2010
Identifier: CFE0003190, ucf:48587
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003190

Title: CHARACTERISTICS OF RED LIGHT RUNNING CRASHESIN FLORIDA.
Creator: Elnashar, Dina, Radwan, Essam, University of Central Florida
Abstract / Description: Red light running is one of the main contributing factors of crashes in urban areas in Florida and the United States. Nationwide, according to preliminary estimates by the Federal Highway Administration (FHWA) 2001, there were nearly 218,000 red-light running crashes at intersections. These crashes resulted in as many as 181,000 injuries and 880 fatalities, and an economic loss estimated at $14 billion per year nationwide, According to the Community Traffic Safety Team Florida Coalition (A...
Show moreRed light running is one of the main contributing factors of crashes in urban areas in Florida and the United States. Nationwide, according to preliminary estimates by the Federal Highway Administration (FHWA) 2001, there were nearly 218,000 red-light running crashes at intersections. These crashes resulted in as many as 181,000 injuries and 880 fatalities, and an economic loss estimated at $14 billion per year nationwide, According to the Community Traffic Safety Team Florida Coalition (A statewide traffic safety group) there were 9,348 crashes involving red-light running in Florida and 127 fatalities in 1999. This research study focused on studying the red light running crashes and violations in the State of Florida. There were three primary objectives for this research. The first primary objective was to analyze the red light running crashes in Florida from 2002 to 2004. The data for this part was collected from the Crash Analysis Reporting System of the Florida Department of Transportation. These crashes are reported as "disregarded traffic signal" as far as the first contributing cause. The analysis focused on the influences of different factors on red light running crashes including the driver (age group, gender, and DUI history) and the environment (time of day, day of week, type of road, and weather). However, not all red light crashes are reported as "disregarded traffic signal". Therefore, representing red light running crashes only through "disregard traffic signal" noted reports would underestimate the extent of red light running effects at a given intersection. Therefore, the second objective was to review the long form crash reports to determine the actual number of crashes related to red light running. The analysis for a random sample of the crashes on the sate roads of Florida on the year 2004 showed that the percentage of crashes related to red light running reported on the database was found to be (3.13%), and the percentage of crashes related to red light running reported in the original crash repot filled by the police officer are much higher than reported(5.63%), which shows the importance of standardizing the format and coding process for the long form crashes conducted by the police officers to help accurately identify the real cause of the crash at the studied location. The third objective was to analyze the violations data given for five intersections and find if there is a correlation between the average rate of violations per hour and the frequency of red light running crashes. The analysis showed that utilizing the limited number of intersections used in the study, it appears that there is no correlation between the average violations per hour and the red light running crashes at the studied locations.
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Date Issued: 2008
Identifier: CFE0002230, ucf:47920
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002230

Title: A Comprehensive Severity Analysis of Large Vehicle Crashes.
Creator: Laman, Haluk, Abdel-Aty, Mohamed, Tatari, Mehmet, Ahmed, Mohamed, University of Central Florida
Abstract / Description: The goal of this thesis is to determine the contributing factors affecting severe traffic crashes (severe: incapacitating and fatal - non-severe: no injury, possible injury, and non-incapacitating), and in particular those factors influencing crashes involving large vehicles (heavy trucks, truck tractors, RVs, and buses). Florida Department of Highway Safety and Motor Vehicles (DHSMV) crash reports of 2008 have been used. The data included 352 fatalities and 9,838 injuries due to large...
Show moreThe goal of this thesis is to determine the contributing factors affecting severe traffic crashes (severe: incapacitating and fatal - non-severe: no injury, possible injury, and non-incapacitating), and in particular those factors influencing crashes involving large vehicles (heavy trucks, truck tractors, RVs, and buses). Florida Department of Highway Safety and Motor Vehicles (DHSMV) crash reports of 2008 have been used. The data included 352 fatalities and 9,838 injuries due to large vehicle crashes.Using the crashes involving large vehicles, a model comparison between binary logit model and a Chi-squared Automatic Interaction Detection (CHAID) decision tree model is provided. There were 13 significant factors (i.e. crash type with respect to vehicle types, residency of driver, DUI, rural-urban, etc.) found significant in the logistic procedure while 7 factors found (i.e. posted speed limit, intersection, etc.) in the CHAID model. The model comparison results indicate that the logit analysis procedure is better in terms of prediction power.The following analysis is a modeling structure involving three binary logit models. The first model was conducted to estimate the crash severity of crashes that involved only personal vehicles (PV). Second model uses the crashes that involved large vehicles (LV) and passenger vehicles (PV). The final model estimated the severity level of crashes involving only large vehicles (LV). Significant differences with respect to various risk factors including driver, vehicle, environmental, road geometry and traffic characteristics were found to exist between those crash types and models. For example, driving under the influence of Alcohol (DUI) has positive effect on the severity of PV vs. PV and LV vs. PV while it has no effect on LV vs. LV. As a result, 4 of the variables found to be significant were similar in all three models (although often with quite different impact) and there were 11 variables that significantly influenced crash injury severity in PV vs. PV crashes, and 9 variables that significantly influenced crash injury severity in LV vs. PV crashes.Based on the significant variables, maximum posted speed, number of vehicles involved, and intersections are among the factors that have major impact on injury severity. These results could be used to identify potential countermeasures to reduce crash severity in general, and for LVs in particular. For example, restricting the speed limits and enforcing it for large vehicles could be a suggested countermeasure based on this study.
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Date Issued: 2012
Identifier: CFE0004566, ucf:49216
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004566

Title: Female student services staff perceptions of safety on a state college campus: An exploratory study.
Creator: Chimera, Catherine, Owens, J. Thomas, Cintron Delgado, Rosa, Preston, Michael, Haciomeroglu, Erhan, University of Central Florida
Abstract / Description: The purpose of this qualitative research study was to explore the perceptions of female student services staff members' perceptions of safety on a state college campus. Through the lens of social construction theory, six staff members were interviewed about their views of safety both on and off campus. The goal of this study was to better understand how female staff members formed their perceptions of safety on campus, through social, political and cultural processes. The results of this...
Show moreThe purpose of this qualitative research study was to explore the perceptions of female student services staff members' perceptions of safety on a state college campus. Through the lens of social construction theory, six staff members were interviewed about their views of safety both on and off campus. The goal of this study was to better understand how female staff members formed their perceptions of safety on campus, through social, political and cultural processes. The results of this study were that although the informants all were aware of the same threats and dangers on campus, they each had differing views on how safe they were while on campus. Of the six interviewed, two expressed daily concern for their safety, two were aware of dangers, but not overly fearful, and two did not feel fearful for their safety at all. Although each informant knew about their campus safety amenities, only two had used their services, one that expressed concern daily, and one that was not overly fearful. Social influences such as televised news programs and Internet articles played a factor in how the employees viewed their safety. Overall, seven major themes were discovered including campus concern, concern over student behavior, self-protection, off campus concerns, social influences, lack of concern, and lack of information. The study concluded with the researcher's recommendations that female student services staff members become knowledgeable about crimes happening on their campuses and about utilizing services they have available to them, as well as emphasizing the importance of office location, especially the proximity to coworkers working similar schedules.
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Date Issued: 2016
Identifier: CFE0006448, ucf:51420
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006448

Title: Dynamic Hotspot Identification for Limited Access Facilities using Temporal Traffic Data.
Creator: Al Amili, Samer, Abdel-Aty, Mohamed, Radwan, Essam, Eluru, Naveen, Lee, JaeYoung, Wang, Chung-Ching, University of Central Florida
Abstract / Description: Crash frequency analysis is the most critical tool to investigate traffic safety problems. Therefore, an accurate crash analysis must be conducted. Since traffic continually fluctuates over time and this effects potential of crash occurrence, shorter time periods and less aggregated traffic factors (shorter intervals than AADT) need to be used. In this dissertation, several methodologies have been conducted to elevate the accuracy of crash prediction. The performance of using less aggregated...
Show moreCrash frequency analysis is the most critical tool to investigate traffic safety problems. Therefore, an accurate crash analysis must be conducted. Since traffic continually fluctuates over time and this effects potential of crash occurrence, shorter time periods and less aggregated traffic factors (shorter intervals than AADT) need to be used. In this dissertation, several methodologies have been conducted to elevate the accuracy of crash prediction. The performance of using less aggregated traffic data in modeling crash frequency was explored for weekdays and weekends. Four-time periods for weekdays and two time periods for weekends, with four intervals (5, 15, 30, and 60 minutes). The comparison between AADT based models and short-term period models showed that short-term period models perform better. As a shorter traffic interval than AADT considered, two difficulties began. Firstly, the number of zero observations increased. Secondly, the repetition of the same roadway characteristics arose. To reduce the number of zero observations, only segments with one or more crashes were used in the modeling process. To eliminate the effect of the repetition in the data, random effect was applied. The results recommend adopting segments with only one or more crashes, as they give a more valid prediction and less error.Zero-inflated negative binomial (ZINB) and hurdle negative binomial (HNB) models were examined in addition to the negative binomial for both weekdays and weekends. Different implementations of random effects were applied. Using the random effect either on the count part, on the zero part, or a pair of uncorrelated (or correlated) random effects for both parts of the model. Additionally, the adaptive Gaussian Quadrature, with five quadrature points, was used to increase accuracy. The results reveal that the model which considered the random effect in both parts performed better than other models, and ZINB performed better than HNB.
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Date Issued: 2018
Identifier: CFE0006966, ucf:51682
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006966

Title: SUPERVISOR EXPECTATIONS, EVENT REPORTING, AND PATIENT SAFETY PERCEPTIONS: EXPLORING POTENTIAL MODERATORS AND MEDIATORS.
Creator: Hernandez, Claudia, Burke, Shawn, University of Central Florida
Abstract / Description: Given the high number of errors and negative events committed within medical settings, the emphasis on patient safety culture is becoming more prevalent. Despite this effort, underreporting has been and continues to be an issue in this area. Some research has shown a link between underreporting and lack of management responsiveness, but more work is necessary to identify reasons for underreporting and potential mitigating solutions. The objective of the present research is to answer questions...
Show moreGiven the high number of errors and negative events committed within medical settings, the emphasis on patient safety culture is becoming more prevalent. Despite this effort, underreporting has been and continues to be an issue in this area. Some research has shown a link between underreporting and lack of management responsiveness, but more work is necessary to identify reasons for underreporting and potential mitigating solutions. The objective of the present research is to answer questions regarding the impact supervisors have on staff's patient safety perceptions and event reporting, through the use of archival survey data collected with the AHRQ Hospital Safety Culture Survey (2004). Probable moderators and mediators of key relationships were explored as well. Results are presented and their implications are discussed herein.
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Date Issued: 2016
Identifier: CFH2000084, ucf:45551
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000084

Title: THE IMPACT OF INTRAORGANIZATIONAL TRUST AND LEARNING ORIENTED CLIMATE ON ERROR REPORTING.
Creator: Sims, Dana Elizabeth, Salas, Eduardo, University of Central Florida
Abstract / Description: Insight into opportunities for process improvement provides a competitive advantage through increases in organizational effectiveness and innovation As a result, it is important to understand the conditions under which employees are willing to communicate this information. This study examined the relationship between trust and psychological safety on the willingness to report errors in a medical setting. Trust and psychological safety were measured at the team and leader level. In addition,...
Show moreInsight into opportunities for process improvement provides a competitive advantage through increases in organizational effectiveness and innovation As a result, it is important to understand the conditions under which employees are willing to communicate this information. This study examined the relationship between trust and psychological safety on the willingness to report errors in a medical setting. Trust and psychological safety were measured at the team and leader level. In addition, the moderating effect of a learning orientation climate at three levels of the organization (i.e., team members, team leaders, organizational) was examined on the relationship between trust and psychological safety on willingness to report errors. Traditional surveys and social network analysis were employed to test the research hypotheses. Findings indicate that team trust, when examined using traditional surveys, is not significantly associated with informally reporting errors. However, when the social networks within the team were examined, evidence that team trust is associated with informally discussing errors was found. Results also indicate that trust in leadership is associated with informally discussing errors, especially severe errors. These findings were supported and expanded to include a willingness to report all severity of errors when social network data was explored. Psychological safety, whether within the team or fostered by leadership, was not found to be associated with a willingness to informally report errors. Finally, learning orientation was not found to be a moderating variable between trust and psychological safety on a willingness to report errors. Instead, organizational learning orientation was found to have a main effect on formally reporting errors to risk management and documenting errors in patient charts. Theoretical and practical implications of the study are offered.
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Date Issued: 2009
Identifier: CFE0002818, ucf:48050
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002818

Title: Investigating and Facilitating the Transferability of Safety Performance Functions.
Creator: Farid, Ahmed Tarek Ahmed, Abdel-Aty, Mohamed, Lee, JaeYoung, Eluru, Naveen, University of Central Florida
Abstract / Description: Safety performance functions (SPFs) are essential analytical tools in the road safety field. The SPFs are statistical regression models used to predict crash counts by roadway facility type, crash type and severity. The national Highway Safety Manual (HSM) is a generic guidebook used for road safety evaluation and enhancement. In it, default SPFs, developed using negative binomial (NB) regression, are provided for multiple facility types and crash categories. Roadway agencies, whether public...
Show moreSafety performance functions (SPFs) are essential analytical tools in the road safety field. The SPFs are statistical regression models used to predict crash counts by roadway facility type, crash type and severity. The national Highway Safety Manual (HSM) is a generic guidebook used for road safety evaluation and enhancement. In it, default SPFs, developed using negative binomial (NB) regression, are provided for multiple facility types and crash categories. Roadway agencies, whether public or private, may opt to not invest their resources in data collection and processing to develop own localized SPFs. Instead, the agencies may adopt the HSM's. However, the HSM's SPFs may not necessarily be applicable to any conditions. Hence, this research is focused on SPF transferability, specifically for rural divided multilane highway segments. Use of Bayesian informative priors to aid in the transferability of NB SPFs, developed for Florida, to California's conditions and vice versa is investigated. It is demonstrated that informative priors facilitate SPF transferability. Furthermore, NB SPFs are developed for Florida, Ohio, Illinois, Minnesota, California, Washington and North Carolina. That is to evaluate the transferability of each state's SPFs to the other states' conditions. The results indicate that Ohio, Illinois, Minnesota and California have SPFs that are transferable to conditions of each of the four states. Also, two methods are proposed for calibrating transferred SPFs to the destinations' conditions and are shown to outperform the SPF calibration methods in the road safety literature. Finally, a variety of modeling frameworks are proposed for developing and transferring SPFs of the seven aforementioned states to each state's data. Not a single model exhibits the best fit when transferred in all cases. However, the Tobit model, NB model and a hybrid model that coalesces the results of both perform the best in a substantial number of the transferred SPFs.
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Date Issued: 2018
Identifier: CFE0007000, ucf:52054
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007000

Title: Assessing the Safety and Operational Benefits of Connected and Automated Vehicles: Application on Different Roadways, Weather, and Traffic Conditions.
Creator: Rahman, Md Sharikur, Abdel-Aty, Mohamed, Eluru, Naveen, Hasan, Samiul, Yan, Xin, University of Central Florida
Abstract / Description: Connected and automated vehicle (CAV) technologies have recently drawn an increasing attention from governments, vehicle manufacturers, and researchers. Connected vehicle (CV) technologies provide real-time information about the surrounding traffic condition (i.e., position, speed, acceleration) and the traffic management center's decisions. The CV technologies improve the safety by increasing driver situational awareness and reducing crashes through vehicle-to-vehicle (V2V) and vehicle-to...
Show moreConnected and automated vehicle (CAV) technologies have recently drawn an increasing attention from governments, vehicle manufacturers, and researchers. Connected vehicle (CV) technologies provide real-time information about the surrounding traffic condition (i.e., position, speed, acceleration) and the traffic management center's decisions. The CV technologies improve the safety by increasing driver situational awareness and reducing crashes through vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I). Vehicle platooning with CV technologies is another key element of the future transportation systems which helps to simultaneously enhance traffic operations and safety. CV technologies can also further increase the efficiency and reliability of automated vehicles (AV) by collecting real-time traffic information through V2V and V2I. However, the market penetration rate (MPR) of CAVs and the higher level of automation might not be fully available in the foreseeable future. Hence, it is worthwhile to study the safety benefits of CAV technologies under different MPRs and lower level of automation. None of the studies focused on both traffic safety and operational benefits for these technologies including different roadway, traffic, and weather conditions. In this study, the effectiveness of CAV technologies (i.e., CV /AV/CAV/CV platooning) were evaluated in different roadway, traffic, and weather conditions. To be more specific, the impact of CVs in reduced visibility condition, longitudinal safety evaluation of CV platooning in the managed lane, lower level of AVs in arterial roadway, and the optimal MPRs of CAVs for both peak and off-peak period are analyzed using simulation techniques. Currently, CAV fleet data are not easily obtainable which is one of the primary reasons to deploy the simulation techniques in this study to evaluate the impacts of CAVs in the roadway. The car following, lane changing, and the platooning behavior of the CAV technologies were modeled in the C++ programming language by considering realistic car following and lane changing models in PTV VISSIM. Surrogate safety assessment techniques were considered to evaluate the safety effectiveness of these CAV technologies, while the average travel time, average speed, and average delay were evaluated as traffic operational measures. Several statistical tests (i.e., Two sample t-test, ANOVA) and the modelling techniques (Tobit, Negative binomial, and Logistic regression) were conducted to evaluate the CAV effectiveness with different MPRs over the baseline scenario. The statistical tests and modeling results suggested that the higher the MPR of CAVs implemented, the higher were the safety and mobility benefits achieved for different roadways (i.e., freeway, expressway, arterials, managed lane), weather (i.e., clear, foggy), and traffic conditions (i.e., peak and off-peak period). Interestingly, from the safety and operation perspective, at least 30% and 20% MPR were needed to achieve both the safety and operational benefits of peak and off-peak period, respectively. This dissertation has major implications for improving transportation infrastructure by recommending optimal MPR of CAVs to achieve balanced mobility and safety benefits considering varying roadway, traffic, and weather condition.
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Date Issued: 2019
Identifier: CFE0007709, ucf:52442
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007709

safety (11)	+ -
Traffic Safety (7)	+ -
Safety (6)	+ -
patient safety (6)	+ -
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Driving Simulator (4)	+ -
Highway Safety Manual (4)	+ -
VISSIM (4)	+ -
human factors (4)	+ -
Empirical Bayes (3)	+ -
Intelligent Transportation Systems (3)	+ -
Patient Safety (3)	+ -
Safety Performance Functions (3)	+ -
driving simulator (3)	+ -
fog (3)	+ -
Crash Modification Factors (2)	+ -
Crash Prediction (2)	+ -
Crashes (2)	+ -
EMS (2)	+ -
GIS (2)	+ -
ITS (2)	+ -
Intersection (2)	+ -
Mobility (2)	+ -
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Negative Binomial model (2)	+ -
Pedestrian Safety (2)	+ -
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Honors Collection (5)	+ -

English (95)	+ -
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University of Central Florida (95)	+ -
Abdel-Aty, Mohamed (46)	+ -
Eluru, Naveen (18)	+ -
Lee, JaeYoung (15)	+ -
Radwan, Essam (12)	+ -

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