Research Papers

Safety Effects of Portable End-of-Queue Warning System Deployments at Texas Work Zones

Filename 1A-Cox-FP.doc
Filesize 2 MB
Version 1
Date added June 29, 2016
Downloaded 9 times/fois
Category 2016 CARSP XXVI Halifax
Tags Policy and Practice, Session 1A
Author/Auteur Gerald L Ullman, Vichika Iragavarapu, Robert E. Brydia
Stream/Volet Policy and Practice

Slidedeck Presentation not available


Background/Context: Inattentive driving, whether caused by distracted or drowsy driving, continues to be a major cause of injury and death on our roadways. The AAA Foundation in their 2013 Traffic Safety Culture Index reported that 67.3% admitted using their cell phone for calls, 25.8% typed emails or texts and 41% reported ‘falling asleep or nodding off’. The Traffic Injury Research Foundation in their 2011 Road Safety Monitor report that 36.3% of drivers report using cell phones for calls while 14.3% of drivers report driving when tired or fatigued. To safely maneuver through a work zone means the driver must be able to recognize lane shifts and stopped or slow vehicles ahead. Drivers that are distracted or drowsy need to be alerted to the upcoming traffic changes presented by the work zone.
Aims/Objectives: The objective of the End of Queue –EOQ – is to make sure that distracted drivers focus on the upcoming work zone and that drowsy drivers become alert to the changing conditions. Secondary objectives are reduction in actual speeds through the work zone and reduction in work zone intrusions into the workspace
Methods/Target Group: This practice is targeted at 3 groups: policy makers at the agency level, drivers approaching road works and contractors performing their work.
Results/Activities: To develop and implement a policy that reduces the effect of distracted, drowsy driving on work zone safety, Texas DOT followed this process. First, they identified these techniques to address distraction: portable temporary rumble strips placed in advance of the lane closure, a monitoring system that calculates queue length in real time and the use of portable, changeable message boards to deliver the real time queue status to drivers. Next, they piloted use of these countermeasures on a variety of roads and traffic conditions. After determining that these practices should become standard for Texas, they developed standard drawings and specifications for future projects. At the same time, they developed a statewide public education campaign to inform drivers and other road users of the new program.
Discussion/Deliverables: The Texas A&M Transportation Institute was contracted to monitor performance of the EOQ system on 1-35 starting in the fall of 2012 until this year. TTI reported a reduction of 41% in severe crashes and 36% in rear-end crashes. Also, there was a reduction in societal crash costs of between $6600 and $10000 for each night that the system was deployed. Though use of the EOQ system, the managers of the construction projects that were part of the I-35 study became more proficient in predicting length of queue so that traffic control device placement was more effective. Texas DOT has been very active in sharing their experiences with peer agencies.

Gerald L Ullman, Vichika Iragavarapu, Robert E. Brydia