Researchers with the Center for Infrastructure-Based Safety Systems (CIBSS) focus their endeavors on roadway-based safety systems such as lighting, visibility treatments, pavement markings, signage, signals, barriers, the interaction of visibility with roadway design and weather considerations. The goal of CIBSS is to conduct research and development efforts that advance knowledge and provide solutions to real-world issues.
This Airport Cooperative Research Program(ACRP)-sponsored project is designed to investigate the functionality and possible energy savings that may result from changes made to airport parking garage lighting. Current lighting technologies will be considered during cost-benefit analyses of transitions to alternative airport parking garage lighting. Activities to be undertaken by VTTI include site selection of multiple airports and field testing using a modified version of the VTTI-developed Roadway Lighting Mobile Measurement System (RLMMS). Lighting design activities will be conducted with assistance from the engineering firm Parsons Brinckerhoff. Cost-benefit analyses of transitions to different parking garage lighting systems will be performed with the assistance of the program management firm, MCR Federal.
The Virginia Center for Transportation Innovation and Research (VCTIR) is sponsoring this assessment of light-emitting diode (LED)-based exterior luminaires. LED luminaires have been tested at VTTI for electrical and lighting performances. Following this laboratory testing, luminaire systems will be evaluated in the field at a Virginia Department of Transportation (VDOT) Park and Ride facility using the VTTI-developed RLMMS. Both evaluations and ongoing measurements of luminaire performance during a 24-month period will be reported to the sponsor to determine what luminaires meet VDOT specifications.
This VCTIR-sponsored project is designed to investigate the performance of internally illuminated roadway signs using different color schemes and intensities to determine which configurations perform best during foggy conditions. A Smart Road study will be conducted during which participants will be asked to read aloud an alphanumeric combination displayed using each sign configuration. The distance at which a participant can correctly read the sign (i.e., the legibility distance) will be used as the measure of performance. Results of this study will provide information that can help increase active sign legibility during foggy conditions.
This VCTIR-sponsored project is another in the Wet Visibility family. Wet Visibility V is an extension of the efforts made during the previous project to assess the durability of pavement markings. The retroreflectivity of test markings installed on Route 460 in Blacksburg, VA, will be monitored for an additional two years to assess long-term durability. The results of this study will provide information about the performance of various pavement markings during a four-year period. Results will be used by VDOT to inform its pavement-marking policies.
This Federal Highway Administration (FHWA)-sponsored project considers the possibilities of adapting lighting systems to the needs of the driving environment. The first step is to create a causal link between the lighting system and the vehicular crash rate. Current projects connect the existence of lighting to a reduction in crashes, but insufficient data exist to link roadway brightness to the crash rate. To accomplish this goal, this project considers the crash rate for six states and performance measurements of the state lighting systems. A Bayesian analysis will then be performed to associate the lighting performance to the crash rate. Draft procedures will be developed to aid in the design of adaptive lighting systems. These procedures will also provide guidelines for when to dim a lighting system and how to perform adaptation. The final step in this project is a legal review of the proposed guidelines to ensure the system viability. The research team is heavily involved in the crash analysis.
This project is sponsored by Clanton and Associates and comprises an LED assessment study conducted in Seattle, WA, in March 2012. The purpose of this study is to compare different LED luminaires to conventional high-pressure sodium (HPS) luminaires at varying dim levels. These comparisons are made to examine the potential to dim roadway luminaires with the goal of conserving energy costs while maintaining the current standard of visibility. Results will inform the City of Seattle and Seattle City Light of potential ways to enhance or maintain visibility while transitioning to LED technology. The results will also exist as a precursor to data that will be collected for the Adaptive Lighting project.
This FHWA-sponsored project was awarded on July 1, 2010. The primary purpose is to provide the FHWA Office of Safety with an outlet for performing various task orders in an indefinite delivery/indefinite quantity (IDIQ) format. This IDIQ contract is competitive. CIBSS researchers successfully provided a response to Task Order Proposal Requests (TOPRs) #30 and #34.
FHWA and the National Highway Traffic Safety Administration (NHTSA) are sponsoring this evaluation of the impact of the spectral power distribution of light on driver performance. With a new focus on energy savings, alternative light source technologies (both traditional and new) are being applied to roadway lighting.
This has caused the spectral power distribution of the light source to play a more important role in the consideration of a roadway lighting application. Broad-spectrum sources (i.e., a light source with significant spectral output across the entire visible spectrum) potentially provide the driver additional benefits such as improved visual performance, better object color recognition, and greater visual comfort. This project investigates these effects and considers the potential benefits of a broad-spectrum source. The project also considers the impacts of both the fixed overhead lighting system and vehicle headlamps. Data collection has been completed; data analysis and final reporting of the project are underway.
This National Cooperative Highway Research Program (NCHRP)-sponsored project investigated the impact of modern headlamp light distribution on visibility through sag vertical curves on roadways. Using the Smart Road and public roads in Blacksburg and Christiansburg, VA, the visibility afforded by a variety of headlamps was measured in terms of object detection distance through a sag vertical curve. This research also included a survey of state departments of transportation (DOTs) and a review of the American Association of State Highway and Transportation Officials (AASHTO) Green Guide. The study found that the AASHTO Green Guide design criteria for sag vertical curves greatly overestimate the visibility facilitated by headlamps; there were no practical changes that could be made to the design criteria to correct the issue.
Wet Visibility IV, sponsored by the Virginia Center for Transportation Innovation and Research (VCTIR), was another in the family of the Wet Visibility projects (see New Projects for a description of the follow-on, Wet Visibility V). This project was designed to evaluate the durability of six wet-night, visible pavement-marking technologies. These materials were installed along Route 460 in Blacksburg, VA. The retroreflectivity of the pavement markings was monitored until April 2011, and the marking durability was evaluated. The visibility performance of the markings was assessed during natural rain conditions. Twenty-four participants from the public were asked to determine the end of the pavement marking, the number of skips visible between markings, and to rate the markings. The final result of this project was a pavement-marking technology durability assessment.
This D.C. Department of Transportation (DDOT)-sponsored project comprised the development of a report recommending strategies and standards for improved lighting methods and levels in the District of Columbia. The project provided information to DDOT about energy-efficient fixtures most suitable for inclusion in the District of Columbia catalogue of standard fixtures. To make appropriate selections of fixtures, VTTI was tasked by SAIC to evaluate fixtures in a lab setting and to collect field data in areas of the District of Columbia. Performance evaluations of the existing District of Columbia lighting system and the final recommended system of fixtures were undertaken by VTTI. Final recommendations were made to the sponsor.