Travis Terry - Academia.edu (original) (raw)
Papers by Travis Terry
Law Enforcement, First Responder and Crash Investigation Preparation for Automated Vehicle Technology
In Pursuit of Emergency Procedures for Automated Driving System-Involved Scenarios
SAE International Journal of Connected and Automated Vehicles, 2021
Moving Towards MAP-21 and Beyond: Creating a GIS Multistate Database to Support Safety Analyses
The Moving Ahead for Progress in the 21st Century Act requires that, as part state highway safety... more The Moving Ahead for Progress in the 21st Century Act requires that, as part state highway safety improvement programs, states have safety-data systems that can be used for performing analyses supporting strategic safety goals and performance-based goals in the State Highway Safety Program (SHSP) and Highway Safety Improvement Program (HSIP) system. This paper describes the structure and attributes of a roadway adaptive lighting database. This database was created as part of the Strategic 6 Initiative for Evaluation of Reduced Lighting on Roadways project. The project is the first modern large-scale study to evaluate the relationship between actual lighting levels and traffic safety using field-collected lighting data, and represents the first effort to collect lighting performance data at a national level. A hierarchical database structure was developed to manage the data and facilitate analysis. These hierarchically-structured data allow users the flexibility to extract desired da...
The NSTSCE stakeholders have jointly funded this research for the purpose of developing and disse... more The NSTSCE stakeholders have jointly funded this research for the purpose of developing and disseminating advanced transportation safety techniques and innovations. The authors are also grateful for the support of Clanton and Associates and Southern California Edison Company. This project was possible only through their support. We would also like to thank BetaLED and Magnaray International for their generous contribution of the lighting systems. iii TABLE OF CONTENTS LIST OF FIGURES .
Comparison of LED Luminaires for Roadway Lighting Using Object Detection and Color Recognition Distances
This study compared two LED luminaires and their abilities to provide detection distance and colo... more This study compared two LED luminaires and their abilities to provide detection distance and color recognition distance of potential roadway hazards. Detection distance is regarded as a metric of visibility. Color recognition distance is a metric for comparing the impact of the CCT (Correlated Color Temperature) of each luminaire and their color contrast impact. Mesopic vision, the mode of vision most commonly used for night driving, was considered in this study. The impacts of luminance and color contrast were addressed in this study. The experiment was performed on the Virginia Smart Road where small wooden targets of different colors and pedestrians wearing different colors were detected by drivers of a moving vehicle in a controlled environment. The key difference between the two luminaires was their color temperatures (3500K versus 6000K). The results indicated that neither light source provided a significant benefit over the other although significant interactions were found a...
This report provides information on the design considerations of the embedded highway lighting de... more This report provides information on the design considerations of the embedded highway lighting design on Interstate-25 in Trinidad, Colorado, in terms of visibility. The information is based on visibility characterizations of small targets using luminance, illuminance, and contrast calculations as well as participant input on the detectability of small targets. Experimental conditions included two different aim angles of the lighting design (forward and cross) as well as two small target colors (red and blue). When compared to the small target detection distances produced by conventional overhead lighting systems in previous studies, the research determined that the small target visibility distances of the embedded lighting design to be shorter by approximately 50%. Adjustments to the spacing, aim, and breadth of the lighting design are recommended for future research considerations. The results of this research indicate the lighting design is an alternative; however, additional con...
Rural Intersection Lighting Safety Analysis
This study compared two LED luminaires and their abilities to provide detection distance and colo... more This study compared two LED luminaires and their abilities to provide detection distance and color recognition distance of potential roadway hazard. Detection distance is regarded as a metric of visibility. Color recognition distance is a metric for comparing the impact of the (Correlated Color Temperature) CCT of each luminaire and their color contrast impact. Mesopic vision, the mode of vision most commonly used for night driving, was considered in this study. Off-axis objects were presented to participants to assess the peripheral abilities of the luminaires. The impacts of luminance and color contrast were addressed in this study. The experiment was performed on the Virginia Smart Road where standard objects of different colors and pedestrians wearing different colors were detected by drivers of a moving vehicle in a controlled environment. The key difference between the two luminaires was their color temperatures (3500K versus 6000K). The results indicated that neither light so...
The project that is the subject of this report was done under contract for the Virginia Departmen... more The project that is the subject of this report was done under contract for the Virginia Department of Transportation, Virginia Transportation Research Council. The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Virginia Department of Transportation, the Commonwealth Transportation Board, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Any inclusion of manufacturer names, trade names, or trademarks is for identification purposes only and is not to be considered an endorsement. Each contract report is peer reviewed and accepted for publication by staff of the Virginia Transportation Research Council with expertise in related technical areas. Final editing and proofreading of the report are performed by the contractor.
Linking Roadway Lighting and Crash Safety
This paper investigates the relationship between the lighting level and vehicle crash rate on roa... more This paper investigates the relationship between the lighting level and vehicle crash rate on roadways. The data were collected through crash databases from selected states and through in-situ lighting measurements on selected roadways. The results indicate that there is a strong relationship between lighting level and crash rates. The data were also investigated to determine if energy could be saved by reducing roadway lighting while maintaining safety. The results regarding the correlation between lighting level and crash rates were divided by roadway class as defined by the states. They were then compared to the Illumination Engineering Society’s (IES) recommended roadway-lighting values for the equivalent IES roadway class. The results show there is the potential to reduce the lighting requirements on highways and freeways by as much as 50% while maintaining traffic safety. Limitations include a lack of data for some roadway types, which can be remedied with better data collecti...
Evaluation of traffic behavior in response to alternative police lighting
Accident Analysis & Prevention, 2020
More than 1500 U.S. law enforcement personnel fatalities occurred from 2007 to 2016, with 39 % of... more More than 1500 U.S. law enforcement personnel fatalities occurred from 2007 to 2016, with 39 % of these related to automobile crashes. This study looked at various types of lighting on police vehicles to determine if changes made to the visibility of a police vehicle can impact the surrounding traffic behavior and increase safety for both law enforcement and the general public. Unmarked and marked police vehicles were positioned behind a civilian vehicle on the shoulder of five different multi-lane highways in Virginia, simulating a routine traffic stop. The data collected indicated that more lighting and the use of red in a light bar impact traffic behavior in terms of merging and speed when passing a police vehicle. The benefits may be attributed to the symbolic influence of red as denoting a different type of emergency than a traffic stop in addition to red's chromatic contrast against the blue sky during the daytime.
Transportation Research Record: Journal of the Transportation Research Board, 2017
Guidelines for the provision of effective nighttime performance of overhead signs were developed.... more Guidelines for the provision of effective nighttime performance of overhead signs were developed. Relevant policies and guidelines with regard to sign lighting currently provide little useful information to determine when sign lighting is needed, and the reference material available to practitioners is out of date. Two complementary nighttime visibility studies were conducted, which were designed to produce results useful in developing updated guidelines for overhead sign visibility. The first was conducted on a closed course and investigated the legibility distances of three sign legend and background configurations under various sign lighting treatments. The second was conducted on the open road. It investigated the effects of sign luminance and visual complexity on the distance at which a driver can read overhead signs during a recognition task. The combined findings were used to develop revised guidelines designed to provide adequate nighttime visibility of overhead signs. The p...
The National Academy of Sciences was established in 1863 by an Act of Congress, signed by Preside... more The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Ralph J. Cicerone is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering.
Road-Surface Contrast and Adaptation of Visibility of Low-Contrast Targets
This study investigated the visibility of low-contrast small targets on a roadway illuminated wit... more This study investigated the visibility of low-contrast small targets on a roadway illuminated with light-emitting diode (LED) lighting. Detection-distance measurements were taken on two pavement types, with multiple roadway-lighting illuminance levels, and with and without headlamps. Contrast, vertical illuminance, and visibility levels were also measured and/or calculated. Results showed that the uniformity of the pavement affected mean detection distance. Concrete pavement had less luminance uniformity and longer mean detection distances, while asphalt pavement had more luminance uniformity and shorter detection distances. When headlamps were on, mean detection distances were shorter, possibly because headlamps create a brighter environment to which the eye adapts, lowering its sensitivity to low-contrast objects. When the vehicle was close to the target, the headlamp light could drown out the contrast between the target and background, making it difficult to detect. In general, the brighter the LED roadway lighting, the longer the detection distances, but the results were not significant in three out of four experimental conditions. Visibility level, calculated using Weber contrast and a number of other factors, did not accurately predict the mean detection distance for two experimental conditions. Those calculations might not fully describe small-target visibility for all roadway conditions.
Toilet foot rest attachment
Lighting Research and Technology, 2015
With the advent of light-emitting diode technology being applied to roadway lighting, the spectra... more With the advent of light-emitting diode technology being applied to roadway lighting, the spectral power distribution of the light source is becoming much more important. In this experiment, the detection of pedestrians at five adaptation levels under three light sources, high pressure sodium and light emitting diodes of two colour temperatures was measured in realistic roadway scenarios. The results show that while the light source type was not significant, an increase in adaptation luminance increased the detection distance. As the offset of the object to the roadway increased, some spectral effects became more significant; however, this effect was not consistent across all angles of eccentricity. The conclusions from this work indicate that mesopic factors may not be applicable on high-speed roads.
Transportation Research Record: Journal of the Transportation Research Board, 2015
Adaptive lighting is an approach to lighting design that proposes to change the light level on a ... more Adaptive lighting is an approach to lighting design that proposes to change the light level on a roadway on the basis of the needs of drivers. A review of the literature and building the connection between crashes and light level allowed the development of a system to select roadway luminance levels and then modify these levels on the basis of the needs of the driver. This adaptive lighting system uses parameters such as traffic volume, ambient light levels, pavement marking quality, intersection density, and, most important, the presence of pedestrians to allow lighting design criteria to be selected through a weighting system. As these parameters (such as traffic volume) change, a new light requirement is determined, and the lighting system can be adjusted with controllable luminaires and a master control system. Guidelines for the implementation of this system and an example are provided.
The Federal Highway Administration's Office of Safety Research and Development serves the highway... more The Federal Highway Administration's Office of Safety Research and Development serves the highway safety community by conducting research that advances safety goals while accommodating practical considerations. The development of methodologies and tools that result from this research can assist practitioners who are looking to make safety-based decisions in the real world. The guidelines presented in this report address the need to maintain the safety effects of roadway lighting while alleviating the budgetary strains associated with the maintenance of the lighting infrastructure. This report establishes a new set of criteria for practitioners to apply to their roadway environment that will identify appropriate lighting levels for given roadway characteristics and usage. Specifically, these guidelines identify the appropriate applications of adaptive lighting on roadways while maintaining the optimal level of safety. The methodology for applying the criteria is based on existing international standards that accommodate different roadway characteristics and usage. Therefore, practitioners will be familiar with the application of the results but will benefit from an enhanced data collection and statistical approaches when considering adaptive lighting applications. The adaptive lighting criteria identified in this report are the first to utilize real-world lighting data collection and robust statistical analysis of crash histories of the associated roadways. Ultimately, these Guidelines will provide practitioners with the evidence-based criteria they need to determine the appropriate application of adaptive lighting systems in their jurisdictions. This allows for the unique opportunity to provide significant cost savings while maintaining the optimal level of safety for roadway users.
This report describes an in-depth effort to assess the impact of roadway lighting on the overall ... more This report describes an in-depth effort to assess the impact of roadway lighting on the overall safety performance of roadways. To accomplish this goal, the research team collected thousands of miles of real-world roadway lighting data and compared the varying lighting levels, roadway characteristics, and traffic volumes with crash history information. This comparison required extensive data manipulation and the use of geospatial linkages to pull the data together in a useable form. A robust statistical analysis of the underlying relationships among these data revealed the effects and limits of lighting on the overall roadway safety performance. The results of this report were used to develop a proposed set of adaptive lighting criteria to assist jurisdictions in making sound safety-based decisions when considering adaptive lighting approaches. In addition, this is the most robust analysis of real-world lighting data conducted to date and is intended to serve as the foundation for future roadway lighting analyses.
Law Enforcement, First Responder and Crash Investigation Preparation for Automated Vehicle Technology
In Pursuit of Emergency Procedures for Automated Driving System-Involved Scenarios
SAE International Journal of Connected and Automated Vehicles, 2021
Moving Towards MAP-21 and Beyond: Creating a GIS Multistate Database to Support Safety Analyses
The Moving Ahead for Progress in the 21st Century Act requires that, as part state highway safety... more The Moving Ahead for Progress in the 21st Century Act requires that, as part state highway safety improvement programs, states have safety-data systems that can be used for performing analyses supporting strategic safety goals and performance-based goals in the State Highway Safety Program (SHSP) and Highway Safety Improvement Program (HSIP) system. This paper describes the structure and attributes of a roadway adaptive lighting database. This database was created as part of the Strategic 6 Initiative for Evaluation of Reduced Lighting on Roadways project. The project is the first modern large-scale study to evaluate the relationship between actual lighting levels and traffic safety using field-collected lighting data, and represents the first effort to collect lighting performance data at a national level. A hierarchical database structure was developed to manage the data and facilitate analysis. These hierarchically-structured data allow users the flexibility to extract desired da...
The NSTSCE stakeholders have jointly funded this research for the purpose of developing and disse... more The NSTSCE stakeholders have jointly funded this research for the purpose of developing and disseminating advanced transportation safety techniques and innovations. The authors are also grateful for the support of Clanton and Associates and Southern California Edison Company. This project was possible only through their support. We would also like to thank BetaLED and Magnaray International for their generous contribution of the lighting systems. iii TABLE OF CONTENTS LIST OF FIGURES .
Comparison of LED Luminaires for Roadway Lighting Using Object Detection and Color Recognition Distances
This study compared two LED luminaires and their abilities to provide detection distance and colo... more This study compared two LED luminaires and their abilities to provide detection distance and color recognition distance of potential roadway hazards. Detection distance is regarded as a metric of visibility. Color recognition distance is a metric for comparing the impact of the CCT (Correlated Color Temperature) of each luminaire and their color contrast impact. Mesopic vision, the mode of vision most commonly used for night driving, was considered in this study. The impacts of luminance and color contrast were addressed in this study. The experiment was performed on the Virginia Smart Road where small wooden targets of different colors and pedestrians wearing different colors were detected by drivers of a moving vehicle in a controlled environment. The key difference between the two luminaires was their color temperatures (3500K versus 6000K). The results indicated that neither light source provided a significant benefit over the other although significant interactions were found a...
This report provides information on the design considerations of the embedded highway lighting de... more This report provides information on the design considerations of the embedded highway lighting design on Interstate-25 in Trinidad, Colorado, in terms of visibility. The information is based on visibility characterizations of small targets using luminance, illuminance, and contrast calculations as well as participant input on the detectability of small targets. Experimental conditions included two different aim angles of the lighting design (forward and cross) as well as two small target colors (red and blue). When compared to the small target detection distances produced by conventional overhead lighting systems in previous studies, the research determined that the small target visibility distances of the embedded lighting design to be shorter by approximately 50%. Adjustments to the spacing, aim, and breadth of the lighting design are recommended for future research considerations. The results of this research indicate the lighting design is an alternative; however, additional con...
Rural Intersection Lighting Safety Analysis
This study compared two LED luminaires and their abilities to provide detection distance and colo... more This study compared two LED luminaires and their abilities to provide detection distance and color recognition distance of potential roadway hazard. Detection distance is regarded as a metric of visibility. Color recognition distance is a metric for comparing the impact of the (Correlated Color Temperature) CCT of each luminaire and their color contrast impact. Mesopic vision, the mode of vision most commonly used for night driving, was considered in this study. Off-axis objects were presented to participants to assess the peripheral abilities of the luminaires. The impacts of luminance and color contrast were addressed in this study. The experiment was performed on the Virginia Smart Road where standard objects of different colors and pedestrians wearing different colors were detected by drivers of a moving vehicle in a controlled environment. The key difference between the two luminaires was their color temperatures (3500K versus 6000K). The results indicated that neither light so...
The project that is the subject of this report was done under contract for the Virginia Departmen... more The project that is the subject of this report was done under contract for the Virginia Department of Transportation, Virginia Transportation Research Council. The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Virginia Department of Transportation, the Commonwealth Transportation Board, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Any inclusion of manufacturer names, trade names, or trademarks is for identification purposes only and is not to be considered an endorsement. Each contract report is peer reviewed and accepted for publication by staff of the Virginia Transportation Research Council with expertise in related technical areas. Final editing and proofreading of the report are performed by the contractor.
Linking Roadway Lighting and Crash Safety
This paper investigates the relationship between the lighting level and vehicle crash rate on roa... more This paper investigates the relationship between the lighting level and vehicle crash rate on roadways. The data were collected through crash databases from selected states and through in-situ lighting measurements on selected roadways. The results indicate that there is a strong relationship between lighting level and crash rates. The data were also investigated to determine if energy could be saved by reducing roadway lighting while maintaining safety. The results regarding the correlation between lighting level and crash rates were divided by roadway class as defined by the states. They were then compared to the Illumination Engineering Society’s (IES) recommended roadway-lighting values for the equivalent IES roadway class. The results show there is the potential to reduce the lighting requirements on highways and freeways by as much as 50% while maintaining traffic safety. Limitations include a lack of data for some roadway types, which can be remedied with better data collecti...
Evaluation of traffic behavior in response to alternative police lighting
Accident Analysis & Prevention, 2020
More than 1500 U.S. law enforcement personnel fatalities occurred from 2007 to 2016, with 39 % of... more More than 1500 U.S. law enforcement personnel fatalities occurred from 2007 to 2016, with 39 % of these related to automobile crashes. This study looked at various types of lighting on police vehicles to determine if changes made to the visibility of a police vehicle can impact the surrounding traffic behavior and increase safety for both law enforcement and the general public. Unmarked and marked police vehicles were positioned behind a civilian vehicle on the shoulder of five different multi-lane highways in Virginia, simulating a routine traffic stop. The data collected indicated that more lighting and the use of red in a light bar impact traffic behavior in terms of merging and speed when passing a police vehicle. The benefits may be attributed to the symbolic influence of red as denoting a different type of emergency than a traffic stop in addition to red's chromatic contrast against the blue sky during the daytime.
Transportation Research Record: Journal of the Transportation Research Board, 2017
Guidelines for the provision of effective nighttime performance of overhead signs were developed.... more Guidelines for the provision of effective nighttime performance of overhead signs were developed. Relevant policies and guidelines with regard to sign lighting currently provide little useful information to determine when sign lighting is needed, and the reference material available to practitioners is out of date. Two complementary nighttime visibility studies were conducted, which were designed to produce results useful in developing updated guidelines for overhead sign visibility. The first was conducted on a closed course and investigated the legibility distances of three sign legend and background configurations under various sign lighting treatments. The second was conducted on the open road. It investigated the effects of sign luminance and visual complexity on the distance at which a driver can read overhead signs during a recognition task. The combined findings were used to develop revised guidelines designed to provide adequate nighttime visibility of overhead signs. The p...
The National Academy of Sciences was established in 1863 by an Act of Congress, signed by Preside... more The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Ralph J. Cicerone is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering.
Road-Surface Contrast and Adaptation of Visibility of Low-Contrast Targets
This study investigated the visibility of low-contrast small targets on a roadway illuminated wit... more This study investigated the visibility of low-contrast small targets on a roadway illuminated with light-emitting diode (LED) lighting. Detection-distance measurements were taken on two pavement types, with multiple roadway-lighting illuminance levels, and with and without headlamps. Contrast, vertical illuminance, and visibility levels were also measured and/or calculated. Results showed that the uniformity of the pavement affected mean detection distance. Concrete pavement had less luminance uniformity and longer mean detection distances, while asphalt pavement had more luminance uniformity and shorter detection distances. When headlamps were on, mean detection distances were shorter, possibly because headlamps create a brighter environment to which the eye adapts, lowering its sensitivity to low-contrast objects. When the vehicle was close to the target, the headlamp light could drown out the contrast between the target and background, making it difficult to detect. In general, the brighter the LED roadway lighting, the longer the detection distances, but the results were not significant in three out of four experimental conditions. Visibility level, calculated using Weber contrast and a number of other factors, did not accurately predict the mean detection distance for two experimental conditions. Those calculations might not fully describe small-target visibility for all roadway conditions.
Toilet foot rest attachment
Lighting Research and Technology, 2015
With the advent of light-emitting diode technology being applied to roadway lighting, the spectra... more With the advent of light-emitting diode technology being applied to roadway lighting, the spectral power distribution of the light source is becoming much more important. In this experiment, the detection of pedestrians at five adaptation levels under three light sources, high pressure sodium and light emitting diodes of two colour temperatures was measured in realistic roadway scenarios. The results show that while the light source type was not significant, an increase in adaptation luminance increased the detection distance. As the offset of the object to the roadway increased, some spectral effects became more significant; however, this effect was not consistent across all angles of eccentricity. The conclusions from this work indicate that mesopic factors may not be applicable on high-speed roads.
Transportation Research Record: Journal of the Transportation Research Board, 2015
Adaptive lighting is an approach to lighting design that proposes to change the light level on a ... more Adaptive lighting is an approach to lighting design that proposes to change the light level on a roadway on the basis of the needs of drivers. A review of the literature and building the connection between crashes and light level allowed the development of a system to select roadway luminance levels and then modify these levels on the basis of the needs of the driver. This adaptive lighting system uses parameters such as traffic volume, ambient light levels, pavement marking quality, intersection density, and, most important, the presence of pedestrians to allow lighting design criteria to be selected through a weighting system. As these parameters (such as traffic volume) change, a new light requirement is determined, and the lighting system can be adjusted with controllable luminaires and a master control system. Guidelines for the implementation of this system and an example are provided.
The Federal Highway Administration's Office of Safety Research and Development serves the highway... more The Federal Highway Administration's Office of Safety Research and Development serves the highway safety community by conducting research that advances safety goals while accommodating practical considerations. The development of methodologies and tools that result from this research can assist practitioners who are looking to make safety-based decisions in the real world. The guidelines presented in this report address the need to maintain the safety effects of roadway lighting while alleviating the budgetary strains associated with the maintenance of the lighting infrastructure. This report establishes a new set of criteria for practitioners to apply to their roadway environment that will identify appropriate lighting levels for given roadway characteristics and usage. Specifically, these guidelines identify the appropriate applications of adaptive lighting on roadways while maintaining the optimal level of safety. The methodology for applying the criteria is based on existing international standards that accommodate different roadway characteristics and usage. Therefore, practitioners will be familiar with the application of the results but will benefit from an enhanced data collection and statistical approaches when considering adaptive lighting applications. The adaptive lighting criteria identified in this report are the first to utilize real-world lighting data collection and robust statistical analysis of crash histories of the associated roadways. Ultimately, these Guidelines will provide practitioners with the evidence-based criteria they need to determine the appropriate application of adaptive lighting systems in their jurisdictions. This allows for the unique opportunity to provide significant cost savings while maintaining the optimal level of safety for roadway users.
This report describes an in-depth effort to assess the impact of roadway lighting on the overall ... more This report describes an in-depth effort to assess the impact of roadway lighting on the overall safety performance of roadways. To accomplish this goal, the research team collected thousands of miles of real-world roadway lighting data and compared the varying lighting levels, roadway characteristics, and traffic volumes with crash history information. This comparison required extensive data manipulation and the use of geospatial linkages to pull the data together in a useable form. A robust statistical analysis of the underlying relationships among these data revealed the effects and limits of lighting on the overall roadway safety performance. The results of this report were used to develop a proposed set of adaptive lighting criteria to assist jurisdictions in making sound safety-based decisions when considering adaptive lighting approaches. In addition, this is the most robust analysis of real-world lighting data conducted to date and is intended to serve as the foundation for future roadway lighting analyses.