Measuring Left-Behinds on Subway

Funding Source: MassDOT

Title: Measuring Left-Behinds on Subway

Date: May 2018

Status: Completed

Summary: The MBTA uses performance measures to monitor its service and measure improvement. This project supports the development of measures that track the customer experience instead of the performance of vehicles. Current measures are based on fare card records and assume that passengers are able to get on the first available vehicle that arrives at a stop or station. There is not currently a way to measure people left behind on subway platforms when vehicles are too full to board. This report presents the development of methods to measure or estimate the number of passengers that are left behind when vehicles are too crowded to board and the distribution of waiting times experienced by passengers, accounting for left-behind passengers. In addition to making use of existing vehicle location data, the study includes evaluation of two potential technologies for measuring passengers: automated passenger counting from surveillance video feeds, and tracking of MAC addresses from Bluetooth and Wi-Fi-enabled wireless devices. The occurrence of at least one passenger being left behind can be estimated with 90% accuracy, and the total number left-behind passengers during a rush period can be estimated within 10%. Challenges and opportunities for the future are identified.