Capturing Driver Behavior by Measuring Time Gap in Freeway Work Zones

Quantifying the impact that a work zone will have on mobility is currently evaluated in driver models used in traffic microsimulation. It is hypothesized in this paper that the car-following behavior specific to freeway work zones is dissimilar to non-work zone conditions. The objective of this study is to use survey techniques to augment the model calibrations to improve the understanding of car-following behavior in a work zone. An Instrumented Research Vehicle (IRV) and a survey are used to capture car-following driver behavior in a work zone. The car-following behavior is classified for each individual driver by his or her mean time gap. The authors demonstrate that the macroscopic effects for the overall driver behavior in terms of time gap increase due to the work zone only during congestion. At the individual level, a large proportion (or 75% of the sample) increased their time gap in the work zone. A decision tree is used to identify which stated behaviors are important in describing the quantitative data collected in the work zone during congestion. The most important variable identified was driver experience. A clear distinction is shown between experienced drivers in both the non-work zone and the work zone with the less experienced drivers having an overall shorter time gap. The findings presented in this paper can be used to improve the performance of driver behavior models specific to work zones. This in return will more acutely forecast the impact a work zone design has on capacity during congestion.