2013 Session: 572

• Estimating the Impacts of Police Traffic Enforcement Stops on Freeway Operations and Capacity
  Abstract: Over the years, some police agencies have sought to be good stewards of urban traffic flow by reducing their emergency lights while on roadside enforcement stops, particularly during rush hour. In just over the last decade however, move over laws have been implemented in every state except Hawaii. These laws create a mandate for motorists to vacate the lane adjacent to the stopped emergency vehicle. Consequently, the traffic impacts of the police enforcement stop have shifted from a distraction that might slow traffic, to a mandate for drivers’ to change lanes or slow down.From a highway capacity standpoint, the enforcement stop can be modeled as a theoretical lane blocking event, adjusted for motorists’ move over compliance. This research examined 13,416 enforcement stops conducted near roadway traffic detectors on Florida freeways. Based on this research, police enforcement stops reduce available capacity between 54 and 58 percent on two-lane freeways, 35 and 41 percent on three lane facilities, 23 and 30 percent on four lane facilities, and 14 and 22 percent where five lanes are present. Regression analysis examined factors to explain the speed of vehicles passing stops and showed that the number of lanes, posted speed limit, and ambient lighting conditions were all statistically significant issues.From a policy standpoint, police should consider using their emergency lighting equipment throughout the duration of enforcement stops since they improve move over compliance and ostensibly safety. Though not modeled implicitly, breakdown is likely not a deterministic measure, so police activity during periods of high traffic flow and congestion should be reserved for compelling traffic safety needs.
  Authors: Carrick, Grady; Washburn, Scott S.
  Authors: Carrick, Grady; Washburn, Scott S.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0631
• Effectiveness and Site Selection Criteria of Red-Light-Running Camera Systems
  Abstract: The objective of this paper was to evaluate the safety effectiveness of automated traffic enforcement systems (i.e., red light running (RLR) cameras) installed at 254 signalized intersections in 32 jurisdictions in Texas. In addition, the criteria of site selection were evaluated to provide analytical resource for camera installation. A before-after study using the Empirical Bayesian (EB) methodology was performed to remove the regression-to-mean bias during the evaluation of treatments. Results indicated significant decreases in all type and right-angle RLR crashes by 20% and 24%, respectively. A significant increase of 37% was discovered concerning rear-end RLR crashes. The study results suggest that a significant safety benefit for red-light cameras is achieved if intersections have four or more RLR crashes per year or have two or more RLR crashes per 10,000 vehicles. Red-light cameras show counter-productive results if intersections experience less than two RLR crashes per year or have one crash per 10,000 vehicles per year.
  Authors: Ko, Myunghoon; Geedipally, Srinivas Reddy; Walden, Troy Duane
  Authors: Ko, Myunghoon; Geedipally, Srinivas Reddy; Walden, Troy Duane
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-3454
• Effects of License Plate Attributes on Automatic License Plate Recognition
  Abstract: This paper describes an experiment designed to develop a comprehensive and thorough understanding of the readability of North Carolina’s license plates with an Automatic License Plate Recognition system. This research focused on law enforcement applications and utilized two infrared camera systems for data collection in a controlled environment involving over 900 license plates. The field test was conducted in a controlled environment under the following settings and conditions: 25 mph test vehicle, nighttime evaluation, closed test track, 40’ spacing of license plates, 9’ lateral offset between license plates and camera, standard-issue and specialty plate types, standard syntax and personalized plates, varying license plate age and condition. The key finding of this research project is that the current, standard issue, blue ink license plate has the highest capture and read rates among plates tested in this study. Factors which decreased the capture and read rates were personalized syntax, specialty license plates, and the presence of stacked characters on a specialty license plate.
  Authors: Findley, Daniel J.; Cunningham, Christopher M.; Chang, Jeffrey Chiaming; Hovey, Kyle Andrew; Corwin, Michael Allan
  Authors: Findley, Daniel J.; Cunningham, Christopher M.; Chang, Jeffrey Chiaming; Hovey, Kyle Andrew; Corwin, Michael Allan
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0281
  Practice-Ready: Yes
• Police Enforcement Strategies and Speed Reduction in Work Zones
  Abstract: Highway work zone safety is a nationwide concern and it will likely draw ever increasing attention as the number of highways that require renovation or maintenance increases. In an effort to improve work zone safety now and in the future, the Indiana Department of Transportation (INDOT) recently established a special fund for work zone speed enforcement and further commissioned the authors of this study to help them achieve the maximum safety benefits within their budget constraint. A previous study by the authors modeled the crash frequency in Indiana work zones with various features, which provided the potential for safety improvement. In this study, the focus is on evaluating the effectiveness of police enforcement strategies in reducing driving speed in work zones. These results will be eventually included in a comprehensive method for optimizing enforcement strategies and resource allocation to improve work zone safety. Different combinations of stationary police enforcement, with or without supplemental variable message signs (VMS), were evaluated in six work zone sites. The authors conducted data collection using experiment design techniques and multilevel linear modeling for the data analysis with the goal of finding the best way to estimate the effectiveness of enforcement strategies. The developed statistical model allows predicting speed reduction as a function of police enforcement elements and roadway characteristics. The results indicate that spreading enforcement resources among multiple work zones is a good strategy instead of concentrating enforcement on a smaller number of work zones. Furthermore, adding VMS with relevant messages about enforcement greatly increases the effectiveness of the enforcement program.
  Authors: Chen, Erdong; Tarko, Andrew P.
  Authors: Chen, Erdong; Tarko, Andrew P.
  Year: 2013
  Document Type: Paper
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0927
  Practice-Ready: Yes
• Effects of License Plate Attributes on Automatic License Plate Recognition
  Authors: Findley, Daniel
  Authors: Findley, Daniel
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0281
• Estimating the Impacts of Police Traffic Enforcement Stops on Freeway Operations and Capacity
  Authors: Carrick, Grady
  Authors: Carrick, Grady
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0631
• Police Enforcement Strategies and Speed Reduction in Work Zones
  Authors: Chen, Erdong
  Authors: Chen, Erdong
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0927
• Police Enforcement Strategies and Speed Reduction in Work Zones
  Authors: Tarko, Andrew
  Authors: Tarko, Andrew
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-0927
• Effectiveness and Site Selection Criteria of Red-Light-Running Camera Systems
  Authors: Walden, Troy
  Authors: Walden, Troy
  Year: 2013
  Document Type: Presentation
  Subject: Operations and Traffic Management; Safety and Human Factors
  Session: 572
  Paper Number: 13-3454