Measuring Improvements in the Movement of Highway and Intermodal Freight
Overview of Indicators Identified in Previous Research
Focus of Past Research and Policy Efforts
This review draws on papers and reports that address attributes of freight movement and characteristics of the highway system. The papers that resulted from these efforts, as well as conversations with contacts, suggest that prior efforts to develop measures to gauge the performance of the highway system as a mover of freight have been limited. Previous research efforts have largely looked at one of two issues:
1) Measures of transportation industry productivity that are not clearly linked to the performance of the highway system; or
2) Measures of highway system performance that are important to highway users in general but not specifically linked to freight.
The first set of measures addresses the efficiency of freight service, but does not address the link between freight productivity and the transportation system. Indicators of labor productivity (e.g., ton-miles per employee), logistics efficiency, and equipment utilization (e.g., percent of truck-miles empty) fall into this category, as do multifactor productivity measures (output per unit of combined labor, capital, and intermediate outputs, weighted in some fashion). These indicators are only indirectly affected by the highway system and fail to provide any indication of the quality of service that shippers are receiving.
The second set of measures addresses aspects of the highway system that are important to highway users, such as speed, safety, and pavement condition. While these characteristics affect freight movement, most studies do not attempt to develop indicators of particular relevance to the productivity of freight movement. They are focused on general indicators of highway performance that affect both commercial traffic and personal travel.
The challenge for FHWA is to identify, and focus on, attributes of the highway system that have a particular significance for freight movement and can be linked to the characteristics of freight service that are important for shippers. The prior effort that most directly tackled the issue of identifying and assessing freight performance indicators is FHWA’s Workshop on Productivity Performance Indicators, held in March 1998. This effort, however, was not focused exclusively on freight movement. A number of other efforts yield useful insights into aspects of the transportation system that are important to freight movement, including costs and quality of service, and potential indicators for measuring freight performance. Taken together, these studies provide a basis for further exploration of this problem.
Indicators identified from prior studies tend to fall into the following seven categories: