Effects of Work Zone Detours on Rural Highway Traffic Operations

The study examines tow US 59 work zone sites and their impact on rural highway traffic. After first recording typical traffic under free-flow conditions (using infrared sensors and reflectors mounted just off the pavement), the researchers then monitored vehicle volume and vehicle speed both during and after work zone construction to identify the traffic operational effects resulting from work zone detours and lane closures. Vehicle speeds, along with the effects of various truck volumes, were analyzed. Two work zone detour strategies were particularly studied: (1) those involving long-term lane closures using concrete barriers, and (2) those involving temporary lane closures using barrel-type barricades. Lane closures involving concrete traffic barriers produced a smaller reduction in free-flow speeds when compared with lane closures of temporary barrel-type barriers. Vehicle speeds through the two work zones were also determined to be influenced by truck volumes and total traffic. Moreover, vehicle speeds were found to vary at different times of the day and during weekdays and weekends. As this study confirmed, lane distribution of traffic on a normal four-lane divided highway varies with increased traffic volume, with a tendency for traffic to distribute equally between the two lanes.