Lane changing is one of the basic driver behavior interactions in microscopic traffic simulations for traffic, safety, and transportation system analysis. Although many traffic simulations pay attention to the decision process for lane changing, the execution process is often simplified or even ignored. This paper presents a study of lane change execution of heavy vehicles and passenger cars in a traffic situation with a blocked lane. A video camera was used to collect data from an arterial road in Melbourne, Australia. This paper investigates the behavior of heavy vehicles and passenger cars in mandatory lane changes and proposes a model framework for the execution of lane changes with regard to the emergency status and the impact of surrounding traffic for individual drivers who are changing lanes. The distance to the blockage was used to denote the emergency status. For the impact of the surrounding traffic, it was assumed that the driver would adjust the execution if a traffic conflict were detected and would continue the lane change if there were no conflict. A probability model was developed to interpret the driver's choice of whether to continue the lane change. The data analysis found that the lane change performance of heavy vehicles differed from that of passenger cars. Therefore, the model was calibrated for heavy vehicles and passenger cars separately. In conclusion, the paper provides a framework of the future work of lane change execution models on traffic simulation to assess the traffic safety and road efficiency.