Capacity restraint functions--which describe travel performance or travel time and delay as a function of the volume using a facility and of the facility capacity--are being used increasingly in the trip distribution and assignment phases of the travel forecasting process. This study discusses the necessity of developing capacity restraint functions for nonsteady-state flows, developing time-of-day capacity restraint and demand functions, and recognizing and dealing with schedule delay in situations where service is infrequent or capacity is restricted. It is concluded that circumstances for nonsteady-state or transient queuing behavior must be included in analyzing performance conditions on travel facilities, and that the quantity of tripmaking to be demanded at any particular time is both time-of-day and travel-service dependent. 22 pp.
This report is part of the RAND Corporation Paper series. The paper was a product of the RAND Corporation from 1948 to 2003 that captured speeches, memorials, and derivative research, usually prepared on authors' own time and meant to be the scholarly or scientific contribution of individual authors to their professional fields. Papers were less formal than reports and did not require rigorous peer review.
Our mission to help improve policy and decisionmaking through research and analysis is enabled through our core values of quality and objectivity and our unwavering commitment to the highest level of integrity and ethical behavior. To help ensure our research and analysis are rigorous, objective, and nonpartisan, we subject our research publications to a robust and exacting quality-assurance process; avoid both the appearance and reality of financial and other conflicts of interest through staff training, project screening, and a policy of mandatory disclosure; and pursue transparency in our research engagements through our commitment to the open publication of our research findings and recommendations, disclosure of the source of funding of published research, and policies to ensure intellectual independence. For more information, visit www.rand.org/about/principles.
The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.