The national Transportation Performance Index combines indicators of supply (availability), quality of service (reliability, predictability, and safety), and utilization (potential for future growth) across all modes of passenger and freight transportation―highway, public transportation, freight railroad, aviation, marine and intermodal―in order to show how well the U.S. transportation system is serving the needs of businesses and the overall U.S. economy. The national results are from 1990 to 2008―the last year for which national-level data is available. A higher index value is better and lower index value is worse. There is no scale (i.e. 0 - 100) for the index.
The national index is 51.24 in 2008, which is a slight improvement from 50.74 in 2007. However, the moving average, which smoothes the annual variations, shows a clear downward trend from 2003 to 2008. This trend reveals that the performance of the U.S. transportation system is not keeping pace with the demands on that system.
From 1990 to 2008, the Transportation Performance Index increased about 6% overall. In contrast, U.S. population grew 22%, passenger travel grew 39%, and freight traffic grew 27%. Given these facts, it is a testimony to business ingenuity that the national results are not worse. Businesses work around transportation challenges by scheduling deliveries in off-peak hours, implementing flexible employee work policies, and substituting information technology for transportation services. There are also countless stories of transportation infrastructure owners using the engineering equivalent of duct tape to hold infrastructure together and crafting creative operational strategies to enhance throughput.
Can the moving average trend be reversed? Without net new investment in transportation infrastructure and a focus on performance, there could be a decline in the index at a rate of nearly one point per year based on an extrapolation through 2015. A change in any one indicator in any one location does little to move the index; however, a 10% improvement in all indicators produces approximately a 20% increase in the index. To have a transportation system that supports a 21st century economy, the United States needs a high level of investment targeted at improving performance across all modes and geographies. There can be no more business as usual.