Until the publication of TCRP Web Document 6, Transit Capacity and Quality of Service Manual (TCQSM), First Edition, the transportation profession lacked a consolidated set of transit-capacity and quality-of-service definitions, principles, practices, and procedures for planning, designing, and operating vehicles and facilities. This is in contrast to the Highway Capacity Manual (HCM) that defines quality of service and presents fundamental information and computational techniques related to quality of service and capacity of highway facilities. The HCM also provides a focal point and structure for advancing the state of knowledge. It is anticipated that the TCQSM will provide similar benefits.

The First Edition of the TCQSM is a start toward providing the transportation industry with a transit companion to the HCM. "Transit capacity" is a multifaceted concept that deals with the movement of people and vehicles; depends on the size of the transit vehicles and how often they operate; and reflects the interaction between passenger traffic and vehicle flow. "Quality of service" is an even more complex concept that must reflect a transit-user's perspective and must measure how a transit route, facility, or system is operating under various demand, supply, and control conditions.

TCRP Project A-15 was a start toward addressing these issues. The objectives of Project A-15 were to (1) define the content of a comprehensive TCQSM, (2) provide transit input to the HCM2000, (3) develop a prioritized research agenda for completing the TCQSM, (4) complete those portions of a TCQSM for which information was available and produce an interim document, and (5) conduct research on one or more high-priority research topics growing out of the research agenda. These objectives were accomplished by the project, which produced a First Edition TCQSM. The first phase of Project A-15 included market research on what potential users would like to see in a TCQSM, assembled and edited existing information on transit capacity, and results of original research on measuring transit quality of service. The TCQSM also introduces a new approach to measuring quality using a six-cell quality-of-service framework as shown:

	Transit Stop	Route Segment	System
Availability	Frequency	Hours of Service	Service Coverage
Quality	Passenger Loading	Reliability	Transit/Auto Travel Time

Despite the contribution of the First Edition of the TCQSM, there are still gaps in coverage. Before the document can acquire stature, the gaps must be addressed and the professional community must be heard through a testing and public comment period. The purpose of this project is to fill known gaps in scope and update the First Edition in response to public comments.

The objective of this project is to develop an updated TCQSM, filling gaps in the current edition and expanding and enhancing the scope. The update will add material addressing quality of service and capacity implications of service for people with disabilities; passenger service times; system availability and coverage; and other characteristics.

Status: Completed. The Transit Capacity and Quality of Service Manual, Second Edition was published as TCRP Report 100. The panel also approved draft updates to the transit chapters of the Highway Capacity Manual 2000 to reflect the work in the TCQSM.  Comments and questions concerning TCRP Report 100 can be sent to the TRB Committee on Transit Capacity and Quality of Service web board at https://webboard.trb.org/default.asp?boardid=87.