How to measure transportation system performance

Measuring transportation performance has become at once more urgent and complicated. Pressures of ITS deployment and accountability contribute to the urgency. Demands for comprehensive measures create complexity. This note proposes a simple performance system, named TransAcct. Its virtues are: attention to the most important measures, use of readily available sensor measurements and processing algorithms, lowcost and incremental implementation. TransAcct is based on experience gained from the I-880 database. The note sketches a scenario indicating how TransAcct would be routinely used by TMC managers and sta , media, and public information providers. \If you cannot tell the VMT on your system yesterday, you cannot hope to manage your system today" attributed to Dolf May (1961)