Estimation of Effectiveness of a Vehicle-Actuated Signal Control System on Work Zone Operations for a Two-Lane Highway

Abstract

Korean two-lane highways take charge of a function to connect arterial roads with major national roads and provide efficient mobility. However, the number of work zones for road construction and expansion is constantly increasing owing to increment of traffic volume. Therefore the number of maintenance projects is also growing to meet the increased need for road maintenance. All projects that require full or partial closure of a two-lane highway create safety problems, because of two-way delays and poor traffic control, especially at night. Flagging is typically used to control traffic in work zones on two-lane highways by closing one lane and alternating traffic movements. Generally, there is a flagger or Time of Day (hereinafter TOD) control and a one- or two-way delay occurs. Poor safety control in work zones can result in a serious accident if a driver has poor visibility. In this study, to diminish these problems, some alternative traffic control systems are indicated such as actuated signal control with fixed all red (hereinafter AFAR) and actuated signal control with dynamic all red (hereinafter ADAR). And the comparison with each traffic control methods is analyzed focused on average control delay and the number of conflicts which take into account various situations as the length of work zone and traffic volume. The signal control methods under investigation were TOD, AFAR, and ADAR. The average control delay per vehicle was used to evaluate the effectiveness of each method, and work zone conflict was used to evaluate safety. ADAR was found to be the most efficient signal control method under most conditions examined, in terms of safety and mobility in work zones on two-lane highways.