The steady growth of commercial truck travel has led to an increasing demand for truck parking spaces at public rest areas and private truck stops on interstate highways in Virginia. This study developed a methodology to determine the supply and demand for commercial truck parking along these corridors. Supply was defined as the number of parking spaces available for commercial truck parking, and demand was defined as the sum of the parking accumulation and illegal parking at a given time. Phase I of this study developed a methodology to determine the supply and demand for commercial truck parking using I-81 in Virginia as a case study. This Phase II study expanded the study to other interstate highways in Virginia, checked the applicability of the parking demand model developed in Phase I, and developed new models when necessary. Extensive data on the characteristics of commercial truck parking and the characteristics of each truck stop and rest area were collected. In addition, truck drivers and truck stop owners/operators were surveyed. The data collected were used to develop models to describe the relationship between parking accumulation and independent variables such as traffic volume on the highway, truck percentage, parking duration, and the distance from a highway to a truck stop. After the applicability of the models was tested, they were used to estimate commercial truck parking demand in 2010 and 2020. Deficiencies of parking spaces with respect to estimated demand were then determined for each truck stop and the entire Virginia interstate highway system. The results indicate that the demand for commercial truck parking at individual truck stops on I-95 exceeds the supply by 10 to 22 percent and that there is no commercial parking shortfall at truck stops along I-64, 1-77, and I-85. However, there are shortfalls at rest areas on I-66, I-77, I-85, and I-95, varying from about 6 percent on I-85 to about 32 percent on I-95. If no new parking spaces are provided and a 5 percent increase in truck travel is assumed, the demand/supply ratio in 2010 for large truck parking on all interstate highways in Virginia will exceed 1.00. This deficiency could be as high as 40 percent on I-95.