Analysis Methodology for Two-Lane Highways with a Lane Closure

The primary objective of this study was to develop an improved analysis methodology for traffic operations on two-lane highways with a lane closure. Previously developed methodologies have lacked field data calibration or have been unable to accommodate a wide range of two-lane highway work zone conditions. This study addressed these two limitations by using video data collected at three two-lane highway work zone sites in Florida to modify and calibrate FlagSim, a microscopic traffic simulation program capable of modeling flagging control on two-lane highways with a lane closure. Additionally, a full vehicle dynamics modeling approach was incorporated into FlagSim to account for the effect of grade on vehicle performance. The revised version of FlagSim was then used to simulate a wide range of input conditions. Results from these simulation runs were used to develop models for work zone travel speed, saturation headway, total queue delay, and maximum queue length. These equations showed that the work zone conditions (e.g., effective lane width and level of construction activity), roadway conditions (e.g., posted speed and grade), and traffic conditions (e.g., percentage of heavy vehicles) on a two-lane highway with a lane closure can significantly impact traffic operations. These models were incorporated into an analysis methodology and spreadsheet tool that can be used to predict the impact of a lane closure on two-lane highway traffic operations.