Traffic Flow Modeling of Diverse Work Zone Activities

What effect does work activity type have on traffic conditions in a work zone? This question has still not been answered satisfactorily in practice. Without knowing the true effect a work activity has on traffic, practitioners are forced to make assumptions while scheduling work. This paper attempts to answer this question by studying the traffic flow characteristics, that is, traffic speed versus flow curves, capacity reduction factors, and free-flow speed reduction factors, for various activities related to construction and maintenance. The importance of the speed–flow curves and reduction factors for work zone planning is also stressed in the latest edition of the Transportation Research Board’s Highway Capacity Manual. This manual recommends capacity and speed reduction factors for work zones, yet does not include specific guidance for including the impact of work activities. Thre e traffic stream models, Gipps, Newell–Franklin, and Van Aerde, were calibrated using field data from St. Louis, Missouri....