Measuring Improvements in the Movement of Highway and Intermodal Freight
Cost measures were identified in a number of earlier efforts for potential use as transportation system indicators. Transportation cost measures identified in previous efforts include:
cost of highway freight per ton-mile
fuel consumption per ton-mile
total public and private costs of travel
maintenance cost of connector links
Transportation costs are important to freight shippers. Lower transportation costs per unit shipped are beneficial to shippers; lower transportation costs contribute to more efficient use of resources in production and distribution. Greater efficiency ultimately benefits consumers in better quality and/or lower prices for goods. Declining costs, however, are not necessarily all positive for freight performance. Lower costs could be the result of lower quality of service (e.g., reduced reliability). There are a number of different types of transportation costs that can be tracked, as described below. Potentially useful cost measures focus on the costs associated with freight transport. Less useful cost measures focus on highway infrastructure costs and expenditures, which may or may not reflect improved freight performance.
Cost per Ton-mile
The first of these measures, cost of highway freight per ton-mile, is certainly a useful measure. It is specific to freight, and is affected by highway conditions. It is also affected by factors unrelated to the highway system, however, such as truck technology, drivers’ wages, fuel costs, and trucking companies’ skill in managing their fleets. As a result, it may be skewed by factors that have nothing to do with transportation infrastructure.
Fuel Consumption per Ton-mile
Fuel consumption per ton-mile, is not really a “cost” measure but it does reflect one of the costs associated with transport that is related to highway condition. It reflects the same things as costs per ton-mile, but would not be affected by the prices of labor and fuel. As a result, it may be a better measure of the performance of highway-system performance in freight carriage because it reflects fewer costs unrelated to highway conditions. It may be more difficult to grasp intuitively as an indicator of freight performance, however.
Total Public and Private Costs of Travel
As noted above, one weakness with cost measures is that they do not account for the quality of service. A measure of total costs attempts to account for this problem by focusing not only on the costs of shipping goods but also costs associated with damage to goods, constructing roads, expanding and maintaining highways, etc. As a result, a measure of total public and private costs of travel takes into account all the resource costs associated with travel.