4: Assessment of the Relationship Between Vehicle Type Mix and the Benefit of Freight Projects

In the first part of this paper, a methodology for estimating the short-run economic impact of freight projects is proposed. The methodology quantifies three types of impacts; savings in travel time and distance, pavement damage, and broad economic development via multiplier effects. In the second part of the paper, the sensitivity of the impacts calculated by the proposed methodology with respect to the breakdown of vehicle miles travelled by vehicle configuration is assessed using a hypothetical road-widening project in Chicago. The analyses revealed that the overall economic impact is not particularly sensitive to the vehicle configuration since the decrease in pavement damage is only a small portion of the overall impact and also other costs are not affected significantly by vehicle configuration. In contrast, the split of the vehicle miles travelled between for-hire and in-house trucks is crucial since it has a direct effect on the value of time and subsequently, the cost reduction associated with travel time saving.