Passenger Car Equivalent (PCE) of heavy vehicles in work zones have not been studied before. In this research, the concept of delay-based PCE is extended for work zones. A mathematical model was developed to determine the bounds on the delays in work zones. Conceptually the work zone is discretized into sections and assuming steady state conditions and using nite second moments, linear programs were formulated to obtain the lower and upper bounds on the average number of vehicles in the work zone. The results of the model for level terrain and upgrades were validated using an independent...