Assessing the Value of Delay to Truckers and Carriers

This thesis evaluates the Value of Delay (VOD) to commercial vehicle operators due to highway congestions. The VOD for congestion is a fundamental parameter driving the private sectors’ response to public freight projects and policies such as corridor construction and tolling. Factors affecting the commercial VOD include direct operational cost, travel length, travel time variation, inventory holding, and warehouse management. To approach the VOD, two methods are adopted in this thesis. One is the Stated Preference (SP) survey. The other is carrier fleet operational simulation. The simulation framework uses ArcGIS, and C . ArcGIS is used to generate a freight network based on the Houston, TX highway system. A set of customers are randomly generated, each having a random demand for service, which is associated with time windows for delivery and pickup. A heuristic algorithm is proposed to dispatch vehicles for truckload service on a continuous time horizon. The average VOD is then obtained through the ratio between additional operational cost and the delay caused by the congestion. This ratio is assessed in two scenarios: single depot and two cooperating depots. Different tests based on demand size, demand distribution pattern, time window and location of congestion are conducted. Simulation shows a range of VOD from $93.99/hr to $120.89/hr for the case of a central depot and $79.81/hr to $83.81/hr for the case of two depots. In addition, a SP survey is conducted for truckers and carriers in two scenarios. The first scenario assumes a driver running late by 30 minutes on a congested road, while the second scenario assumes an on-time delivery or pickup. Several tolling alternatives are assumed to test the driver’s willingness to pay for using a hypothetical toll road. The data is then regressed with the logit model using maximum likelihood estimation to obtain perspective value of delay. A generic utility function is adopted, which results in a VOD range from $24.72/hr to $64.99/hr. A comparison between the survey and the simulation results shows that drivers perceive a significantly lower VOD than the simulated VOD in freight operation