Numerous states have policies that provide guidance for the institution of short term lane closures on arterial streets based on capacity estimates, however it is not clear how the existing values were developed, and there are currently no tools to estimate the capacity of arterial lane closures. Capacity is estimated as a function of various factors including the percent of left turning vehicles, the distance of the work zone to the downstream intersection, and the g/C (effective green to cycle length) of each lane group. The following were concluded from the research: 1) Simulation of arterial work zones showed that the distance of the work zone to the downstream intersection affects the capacity of the entire arterial work zone. Increasing the available storage between the signal and the work zone models results in better utilization of the green time at the intersection approach. 2) The capacity is reduced when one of the movements are blocked by the other. 3) Comparison of the arterial work zone capacity to the respective configurations with no work zone showed that there are selected cases when installing a work zone may increase capacity. Those increases typically occur when the intersection (prior to the work zone installation) is congested.