Safety Evaluation of Red-light Indicator Lights (RLILs) at Intersections PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Safety Evaluation of Red-light Indicator Lights (RLILs) at Intersections PDF full book. Access full book title Safety Evaluation of Red-light Indicator Lights (RLILs) at Intersections by Scott Himes. Download full books in PDF and EPUB format.
Author: Scott Himes
Publisher:
ISBN:
Category : Accidents
Languages : en
Pages : 46
Get Book Here
Book Description
The Development of Crash Modification Factors program conducted the safety evaluation of red-light indicator lights (RLILs) at intersections for the Evaluation of Low-Cost Safety Improvements Pooled Fund Study. This study evaluated safety effectiveness of RLILs. RLILs are auxiliary lights mounted on signal heads, mast arms, or poles that are directly connected to a traffic-control signal. The RLIL activates at the onset of the red phase and allows an enforcement officer to observe red-light running from downstream of the intersection. This strategy is intended to reduce the frequency of crashes resulting from drivers disobeying traffic signals by providing a safer and more efficient means for police to enforce the red interval. Geometric, traffic, and crash data were obtained at treated four-legged signalized intersections in Florida. To account for potential selection bias and regression-to-the-mean, an empirical Bayes before–after analysis was conducted using reference groups of untreated four-legged signalized intersections with characteristics similar to those of the treated sites. The analysis also controlled for changes in traffic volumes over time and time trends in crash counts unrelated to the treatment. Results indicate statistically significant crash reductions for most crash types. Disobeyed signal crashes had an estimated crash modification factor (CMF) of 0.71. Total crashes, fatal and injury crashes, right-angle, and left-turn crashes had estimated CMFs of 0.94, 0.86, 0.91, and 0.60, respectively. The benefit-cost ratio estimated with conservative cost and service life assumptions was 92:1 for four-legged signalized intersections. The results suggest that the treatment, even with conservative assumptions on cost, service life, and the value of a statistical life, can be cost effective. In addition to the crash-related benefits, RLILs can improve the efficiency and safety of red-light running enforcement efforts. While this study did not evaluate the efficiency and safety impacts with respect to enforcement, it should be noted that RLILs do allow police to observe violators from a downstream position, eliminating the need for a second observer (upstream) and the need to pursue a violator through the red light.
Author: Scott Himes
Publisher:
ISBN:
Category : Accidents
Languages : en
Pages : 46
Get Book Here
Book Description
The Development of Crash Modification Factors program conducted the safety evaluation of red-light indicator lights (RLILs) at intersections for the Evaluation of Low-Cost Safety Improvements Pooled Fund Study. This study evaluated safety effectiveness of RLILs. RLILs are auxiliary lights mounted on signal heads, mast arms, or poles that are directly connected to a traffic-control signal. The RLIL activates at the onset of the red phase and allows an enforcement officer to observe red-light running from downstream of the intersection. This strategy is intended to reduce the frequency of crashes resulting from drivers disobeying traffic signals by providing a safer and more efficient means for police to enforce the red interval. Geometric, traffic, and crash data were obtained at treated four-legged signalized intersections in Florida. To account for potential selection bias and regression-to-the-mean, an empirical Bayes before–after analysis was conducted using reference groups of untreated four-legged signalized intersections with characteristics similar to those of the treated sites. The analysis also controlled for changes in traffic volumes over time and time trends in crash counts unrelated to the treatment. Results indicate statistically significant crash reductions for most crash types. Disobeyed signal crashes had an estimated crash modification factor (CMF) of 0.71. Total crashes, fatal and injury crashes, right-angle, and left-turn crashes had estimated CMFs of 0.94, 0.86, 0.91, and 0.60, respectively. The benefit-cost ratio estimated with conservative cost and service life assumptions was 92:1 for four-legged signalized intersections. The results suggest that the treatment, even with conservative assumptions on cost, service life, and the value of a statistical life, can be cost effective. In addition to the crash-related benefits, RLILs can improve the efficiency and safety of red-light running enforcement efforts. While this study did not evaluate the efficiency and safety impacts with respect to enforcement, it should be noted that RLILs do allow police to observe violators from a downstream position, eliminating the need for a second observer (upstream) and the need to pursue a violator through the red light.
Author: Scott Himes
Publisher:
ISBN:
Category : Red light running
Languages : en
Pages : 8
Get Book Here
Book Description
Technical summary of the Federal Highway Administration report about the effectiveness of red-light inidicator lights (RLILs).
Author:
Publisher:
ISBN:
Category : Red light running
Languages : en
Pages : 8
Get Book Here
Book Description
Technical summary of the Federal Highway Administration report about the effectiveness of red-light inidicator lights (RLILs).
Author: Cynthia Munoz
Publisher: Nova Science Publishers
ISBN: 9781634834483
Category : Photography in traffic engineering
Languages : en
Pages : 0
Get Book Here
Book Description
Red light running is one of the major causes of crashes, deaths, and injuries at signalised intersections. The Federal Highway Administration (FHWA) and National Highway Traffic Safety Administration (NHTSA) support a comprehensive approach to intersection safety that incorporates engineering, education, and enforcement countermeasures to prevent red light running and improve intersection safety. Red light cameras can be a very effective countermeasure to prevent red light running. There are a number of studies that indicate reduction in crashes at signalised intersections due to red light cameras. The fundamental objective of the research in this book is to determine the effectiveness of RLC systems in reducing crashes. A description of all project efforts is described in this book.
Author: James A. Bonneson
Publisher:
ISBN:
Category : Law enforcement
Languages : en
Pages : 122
Get Book Here
Book Description
The objectives of this research project are to: (1) quantify the safety impact of red-light-running at intersections in Texas, and (2) provide guidelines for identifying truly problem intersections and whether enforcement or engineering countermeasures are appropriate. This report documents the findings from the first year of a two-year project. During the first year, data were collected to quantify the character and extent of red-light violations and related crashes in Texas. Data were also collected to quantify the effectiveness of intersection traffic control enforcement. The findings from a review of the literature on red-light-running and an analysis of red-light-running crash data are included in this report. A procedure for identifying and quantifying red-light-running-related crashes is described.
Author: Ramesh Otturu
Publisher:
ISBN:
Category :
Languages : en
Pages : 154
Get Book Here
Book Description
The main objective of this thesis is to evaluate the effectiveness of red light cameras (RLCs) in improving safety at signalized intersections. Two scenarios were considered in order to evaluate the effectiveness of RLCs. Firstly, crashes before the installation of RLC were compared with crashes after the installation of RLC. Secondly, crashes after the installation of RLC were compared with crashes after the termination of RLC. Considering both the scenarios helps to determine whether the safety increased or decreased after the installation and after the termination of RLC. This study used red light running crashes and total crashes to evaluate the effectiveness of RLCs. Data for 36 intersections in the city of Charlotte, NC, where RLCs were installed in 1998 and terminated in 2005, were used for evaluation. The year 1997 was considered as before the installation period while 1999 to 2004 was considered as after the installation period. The year 2005 to 2010 was considered as after the termination period. Data for years 1998 and 2005 was not considered to minimize novelty effects. Variables such as the number of lanes, skewness, the number of thru lanes, the number of approaches and traffic volume were used to develop safety performance function for before the installation period and after the installation period. In before and after the installation scenario, the actual number of red light running and total crashes expected to happen were estimated if the RLC was not installed. The estimated number of crashes were compared with the actual number of crashes occurred at the study intersections after the installation of RLC. The RLC system was considered effective if a decrease in the number of crashes was observed after the installation of RLC. In after installation and after termination scenario, the actual number of red light running and total crashes expected to happen if the RLC was not uninstalled was estimated. The estimated number of crashes were compared with the actual number of crashes occurred at study intersections after the termination of RLC. The RLC system was considered effective if an increase in the number of crashes was observed after the termination of RLC. Rear-end crashes increased by 2.5% after the RLCs were installed while they decreased by 45% after the system was terminated. Sideswipe crashes decreased by 44% after installing the RLCs while they decreased by 50% after the system was terminated. Likewise, angle crashes decreased by 37% after installing the RLCs whereas they decreased by 5% after the system was terminated. Left turn crashes decreased by 2.8% after installing the RLCs while they decreased by 51% after terminating the RLCs. In addition, red light running crashes increased by 21.6% after installing the RLCs while they increased by 10.9% after the system was terminated. Total crashes increased by 16% after the RLCs was installed while they decreased by 55.9% after the system was terminated. After installing RLCs, the number of intersections where sideswipe crashes increased was 17 whereas the number reduced to 5 intersections after terminating RLCs. In the case of left-turn crashes the number of intersections where left-turn crashes increased was 10 intersections whereas the number reduced to 2 intersections after the termination of the RLCs. On the other hand, the number increased from 13 to 24 intersections in the case of rear-end crashes, and 4 to 6 intersections in the case of angle crashes. Empirical Bayes method was used to evaluate the effectiveness of RLC system. Results obtained show that the RLC is not effective in reducing the crashes. Data showed an increase in the number of crashes after the installation of RLCs at the study intersections. After installing the RLCs, red light running crashes increased by 5.7% while they decreased by 1.1% after terminating RLCs. On the other hand, the total number of crashes increased by 4.4% after RLCs were installed whereas they decreased by 2.3% after terminating the RLC. After installing RLCs, the number of intersections where red light running crashes increased was 11 whereas the number reduced to 6 intersections after the termination of the RLCs. Overall a 45% decrease in the performance of number of intersections was observed after the termination of the RLCs. In total crashes scenario, after installing RLCs, the number of intersections where total crashes increased was 9 whereas the number increased to 11 intersections after the termination of the RLCs. Overall a 18% increase in the performance of number of intersections was observed after the termination of RLCs.
Author: Kerrie Schattler
Publisher:
ISBN:
Category : Accidents
Languages : en
Pages : 57
Get Book Here
Book Description
Author: Tomas Lindheimer
Publisher:
ISBN:
Category :
Languages : en
Pages : 156
Get Book Here
Book Description
Red Light Running (RLR) is a safety concern for communities nationwide. The Federal Highway Administration (FHWA) reported that a total of 676 fatalities in 2009 were due to RLR. There are many strategies to mitigate RLR violations that fall in the categories of engineering, enforcement, or education. This research project focused on confirmation lights, a low-cost countermeasure which enhances enforcement at four-approach intersections. Confirmation lights were deployed at two intersections in Overland Park, Kansas. Traffic was observed at the treatment sites, nearby signalized intersections (spillover), and control sites. Traffic was recorded before deployment, 1 month after, and 3 months after deployment. A total of 14 intersections were recorded during the morning peak hours (7 a.m. to 9 a.m.) and the afternoon peak hours (4 p.m. to 6 p.m.) for a total of 583 hours of traffic video. A test of proportions showed that overall the confirmation lights did not significantly reduce RLR violations. A violation analysis showed that there was a global increase in RLR violations after deployment, indicating that other factors were involved in the increase of violations observed. Time into the red analysis showed that the majority of RLR violations occurred within 1 second into the red. The negative binomial regression model re-affirmed that the confirmation lights were not a significant factor in the RLR violations observed. The model showed that lane volume, presence of a right-turn lane, and traffic movement (left or through movement) were significant factors.
Author: Hugh W. McGee
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 76
Get Book Here
Book Description
Author: Sunanda Dissanayake
Publisher:
ISBN:
Category : Automobile drivers
Languages : en
Pages : 0
Get Book Here
Book Description
"Red light running has become a serious safety issue at signalized intersections throughout the United States. One objective of this study was to identify the characteristics of red-light-running (RLR) crashes and the drivers involved in those crashes. Driver characteristics, time and day of the crash, occupancy of the vehicle, and environmental factors were tested against any relationship with the RLR crashes and other signalized intersection (non-RLR) crashes. The other objective was to evaluate the effectiveness of retro-reflective signal backplates in reducing red light running as a low cost countermeasure. Crashes that happened in the State of Kansas were analyzed as a case study. Contingency table was used to identify whether a particular factor is related to the crash type, i.e. RLR vs non-ROR. Two methods were used to evaluate the effectiveness of reflective backplates: cross-sectional analysis using an intersection with reflective backplates and an intersection without reflective backplates, and a before-and-after study using four intersections. According to the results of contingency table analysis, the driver age and safety equipment usage, injury severity of the driver, crash severity, time and day of crash, adverse weather conditions, and surface condition were related to crash type. Variables such as gender of the driver, light condition, and presence of passengers were not related to the crash type. The cross-sectional analysis found that reflective backplates are effective in reducing red light violations in the through and left turning traffic flows. The before-and-after study showed a significant reduction in red light violations in one of the two treatments sites, according to paired-t-test statistics. The reduction of red light violations was not significant in the other. Both analysis could not prove a significant impact on red light violations among the right turning vehicles" (page viii).
