Measurement of Subway Service Performance at New York City Transit

Abstract

A recurring challenge that faces transit managers today is the persistent question of how to do more with less: to maintain and to improve service despite deficits of historic proportions. New York City Transit (NYCT) responded by retooling performance measurement frameworks and procedures to capture the customer's perspective better, to respond to management initiatives, and to incentivize proper operating decisions. NYCT's primary performance measure, Wait Assessment (WA), measured customer maximum wait times to board at stations. A reach and match algorithm was developed; this algorithm was defined as the percentage of headways between trains that did not exceed 125% of scheduled headways. The purpose of the algorithm was to account for NYCT's irregularly scheduled service and to ensure that the way customers experienced headways matched the specific, published scheduled headway in effect at that moment, regardless of which scheduled trip was supposed to arrive. Sample-based methods that gathered limited data manually were upgraded, and track-occupancy data were downloaded from the automated train supervision system for the Number 1 through Number 6 routes. This action provided 100% coverage, which resulted in much lower public reporting of time lags and in the ability to take near-term corrective action. The increase in data availability also allowed NYCT to provide better service through improved consideration of corridor-level and track-level WA standards for internal diagnostic purposes and analysis of train performance in shared-track territory, regardless of route designation.