TRANSIT PERFORMANCE MEASURES

The quality of transit services is evaluated using two performance measures: passenger crowding and on-time performance (called schedule adherence).

A description of the performance measures is presented below, along with a discussion of the thresholds for violation of performance standards. These are based on measures and standards used by the MBTA for service planning purposes.[1] Data on Silver Line performance were not available for this report.

The data used for these measures are collected by CTPS through pointchecks and ridechecks for buses, and via station entrance counts for rapid transit and light rail. Conductors perform commuter rail ridership counts, and the contractor who provides the commuter rail service records schedule adherence information.

Compliance assessments of transit services and benefits were conducted for the 2005 MBTA Title VI Report. (link to the study on our Reports page) Chapter 4 contains a discussion on vehicle load and vehicle headway performance.

On-Time Performance (Schedule Adherence)
The MBTA has established schedule-adherence (on-time) performance thresholds for all of its services, as shown in the table below. In the case of bus performance, the CMS analysis uses an on-time performance measures that is based only on arrivals, not departures. Off-time arrivals are defined as any bus trip (those with at least 10-minute headways) that arrives at its terminus more than two minutes earlier, or five or more minutes later, than its scheduled arrival time. A bus route meets the performance standard if 60 percent or more of morning and evening peak-period trips arrive on time; if less than 60 percent of peak-period trips arrive on time, the route is flagged as a mobility concern. This threshold is different from that used by the MBTA for its service planning, because the CMS analysis is designed to link poor bus on-time performance to congested roadway conditions during the peak periods.

Since roadway congestion is generally the primary cause for late arrivals by buses, this measure ties roadway and transit performance together and should lead to corridor studies that benefit both automobile and transit users.

Passenger Crowding
Passenger crowding is measured in terms of passengers per available seats. A value at or above the established threshold indicates crowded conditions. MBTA thresholds for passenger crowding are used.Notes:

1. Massachusetts Bay Transportation Authority, Service Delivery Policy, September 1996; and Changes to Service Delivery Policy, adopted December 2002. (The 2004 Service Plan was approved by the MBTA Board of Directors in September 2004.) The latest documents are available at www.mbta.com/insidethet/serviceplan.asp.

Transit Performance Thresholds: Passenger Crowding and On-Time Performance
Where the CMS’s performance measure differs from the MBTA-adopted measure, this table also provides the latter.

* For the measures reported in this document, peak period is defined by the MBTA as: morning peak = 7:00 AM–9:00 AM; evening peak = 4:00 PM–6:00 PM. In December 2002, the MBTA adopted a new evening peak period, defined as service from 4:00 PM–6:30 PM.