Field Evaluation of Motorist Reactions to Reduced Work Zone Speed Limits and Other Work Zone Conditions

Abstract

Many factors are taken into consideration in procedures to determine whether a reduced regulatory speed limit in a work zone is warranted. Low levels of compliance with work zone speed limits continue to show, however, that there is a disconnect between procedures to establish regulatory speed limits and motorists’ actual choice of speed in work zones. An improved understanding of how the conditions used to justify reduced speed limits in work zones actually affect speeds could improve the speed limit selection process. To address this need, researchers conducted field studies in Texas work zones to determine motorists’ speed choices adjacent to conditions that were used to warrant reduced speed limits. On the basis of the findings, researchers concluded the following: when no work zone conditions were apparent, speeds downstream of reduced work zone speed limit signs decreased only slightly, independent of the speed limit reduction. Motorists reduced their speeds in work zones when they perceived a need to do so. How much speed was reduced, however, appeared to depend on the normal operating speed of the roadway, the imposing nature of the situation, and enforcement activities. Some work zone conditions used to justify reduced speed limits were not adequately perceived by motorists. Thus it was these conditions that were most in need of enforcement, because motorists were less likely to reduce their speeds voluntarily. Reduced work zone speed limits that were left in place when conditions did not warrant them led to high levels of noncompliance.

Identifying Effects and Applications of Fixed and Variable Speed Limits

“…This has led to numerous projects and research in the area of speed and speed limits. Many research projects have been designed to characterize the effect of speed limits, both in the driver behavior area as well as from a traffic safety perspective (Brewer, Pesti, & Schneider, 2006;Finley, 2011;Garber & Graham, 1990;Haglund & Aberg, 2000). Recently, much of the focus on speed limit studies has been encouraged by a rising interest in variable speed limit signs (Papageorgiou, Kosmatopolous, & Papamichail, 2008;USDOT, 2012).…”

“…No previous studies have used vehicle-matching to compare spot speeds and evaluate speed regulation devices. Some examples of the regulation devices evaluated in previous studies include speed radar cameras (Al-Ghamdi, 2006;Benekohal, Chitturi, Hajbabaje, Wang, & Medina, 2008;Oei, 1996), police presence (Al-Ghamdi, 2006;Wasson et al, 2011), speed-activated warning signs (Brewer et al, 2006;Mattox, Saradua, Ogle, Eckenrode, & Dunning, 2007;Oei, 1996;Santiago-Chaparro, Chitturi, Bill, & Noyce, 2012;Woo, Ho, & Chen, 2007), static speed limits (Agent, Pigman, & Weber, 1998;Finley, 2011;Binkowski, Maleck, Taylor, & Czewski, 1998;Remias, Mekker, McNamara, Sturdevant, & Bullock, 2015;Thornton & Lyles, 1996), and variable speed limits (Edara, Sun, & Hou, 2013;Habtemichael & de Picado Santos, 2013;Lu & Shladover, 2014;Lu, Varaiya, Horowitz, Su, & Shladover, 2011;MDOT, 2004;Riffkin, McMurty, Heath, & Saito, 2008;Weikl, Bogenberger, & Bertini, 2013). These studies are evenly split between work zone and non-work zone speed regulation.…”

Shock Wave Boundary Identification Using Cloud-Based Probe Data

“…However, other agencies may have a different perspective and may select a delta speed of more or less than −15 mph as an appropriate threshold (17). Crashes, construction and maintenance work, and recurring congestion can reduce roadway capacity and form queues to trigger large negative delta speed values, especially on roadways where higher speed limits are in place upstream (18). Figure 2, a and b, shows the location of a crash on southbound I-69 on the morning of May 9, 2014, where two construction workers were fatally struck by a semi tractor trailer that failed to merge properly when entering a construction zone.…”

Assessment of Speed Limit Locations Using Crowdsourced Probe Vehicle Data

“…As a result there have been numerous projects and research in the area of speed and speed limits. Many research projects have been designed to characterize the effect of speed limits, in the driver behavior area as well as from a traffic safety perspective (1)(2)(3)(4). Garber and Graham investigated the increase in fatalities as a result of an increased speed limit (1).…”