Hany M. Hassan

Impact of Red Light Enforcement Cameras on Safety Performance at Signalized Intersections in Abu Dhabi, United Arab Emirates

Red light running crashes have always been a major concern to both researchers and practitioners. In Abu Dhabi, United Arab Emirates, the red light crashes contribute to about 60% of the total severe crashes at signalized intersections. This fact called for a project in 2013, for which new red light cameras (RLCs) were planned to cover 150 intersections in Abu Dhabi City. With the completion of the second stage of this project, 36 signalized intersections have been covered either fully (all intersection approaches) or partially (only major approaches) with a total of 108 RLCs. These RLCs are now in place and have been fully functioning since January 2014. The primary aim of this study was to examine the impact of the installed RLCs on the traffic safety performance in the city. To waive the effects of other factors, two groups were created; they include a study group (36 signalized intersections with RLCs) and a comparison group (36 similar intersections without RLCs). The results indicate a reduction of about 40% to 52% for the number of crashes and 48% to 60% for the number of fatalities and injuries. The majority of at-fault drivers were young male drivers from Asian countries with read-and-write educational level. Moreover, crashes, fatalities, and injuries were modeled using the negative binomial technique. Among 13 tested variables describing the traffic exposure, traffic violations, number of lanes, and coverage of intersections by RLCs, only the number of lanes was found significant in two significant models.

Exploring the nature and severity of heavy truck crashes in Abu Dhabi, United Arab Emirates

Traffic crashes involving heavy trucks long have been a major concern in the field of traffic safety because of their great effect on accident severity. The emirate of Abu Dhabi, capital of the United Arab Emirates, features a unique situation: several roads designed mainly for truck movement. Even though those roads were constructed more than 10 years ago to decrease the severity of truck-related crashes, no prior studies have examined their effects on traffic safety improvements. The goals of this study were to understand better the nature, characteristics, and causes of heavy truck crashes occurring in Abu Dhabi; to identify the factors associated with crash severities; and to examine the probability of truck crashes involving fatalities on truck roads versus on mixed-vehicle roads. Data were analyzed from a sample of 1,426 heavy truck–related crashes with reported fatalities or injuries that occurred in Abu Dhabi between 2007 and 2013. First, conditional distributions, two-way analysis, and odds ratios were performed. Second, ordered probit and structural equation models were developed. Results indicated that the likelihood of truck crashes involving fatalities was 35% higher on truck roads than on mixed-vehicle roads. In addition, findings showed that human error, driver education, location, road type, and road speed variables were significant in affecting the severity of heavy truck– related crashes. Finally, practical suggestions on how to reduce the number of heavy truck–related crashes in Abu Dhabi are presented and discussed.