A method to estimate urban work zone intersection capacity under multiple influencing factors

Work zones generate significant congestion in urban centers, yet the influence of various capacity factors in urban arterials and intersections are poorly understood. This paper analyzes the influence of the following factors on urban arterial and intersection work zone capacity from 22 intersections: heavy vehicle flow, heavy vehicle percentage, work zone length, maximum speed limit, entrance lane width, left turn volumes, entrance and exit lane width reductions, and intersection length and width. An urban work zone was modeled using VISSIM simulation software, and regression models were developed based on the reduction coefficients with MATLAB software for fitting analysis. The results show that the proposed model estimated work zone capacity with high accuracy. Urban work zones were found to reduce capacity by 64% in the selected arterial and by 35% in the selected intersection, with corresponding increases in delay and queue length. The model also estimates the capacity improvement that can be expected given various mitigation factors. Transportation agencies may find work zone capacity estimates useful when planning construction in critical urban centers.