Politics and technical uncertainty in transportation investment analysis

Abstract

Cities often opt for rail transit even when agency evaluations conclude that other alternatives are superior in performance and efficiency. The choice of light rail transit (LRT) in Sacramento, California serves as a case study. When adjustments are made for overstated assumptions and irregular manipulations of data in the Sacramento evaluation, the LRT project is somewhat inferior on all technical grounds to other proposed alternatives. This article asks why a local decision was made to pursue the light rail option. The LRT choice is examined in the broader context of government structure and decision-making, earmarked state and federal funding, and local planning. It is shown that local decision makers have broad economic and social concerns that are not incorporated into standard technical evaluations, and that they are provided with highly uncertain projections, especially for ridership. Not surprisingly, local politicians were skeptical of the technical evaluations and weighed local values and strategic funding factors heavily in their decision. While we do not advocate porkbarreling, we believe that the choice of LRT, to the extent that it reflected legitimate local concerns, was valid. We suggest improvements in transit evaluation methods and observe that the 1984 changes in UMTA evaluation procedures appear to consider uncertainty correctly and to include local political support in a meaningful way.