Distribution of Delay in Signalized Intersections: Day-to-Day Variability in Peak-Hour Volumes
Publication: Journal of Transportation Engineering
Volume 138, Issue 9
Abstract
The Highway Capacity Manual (HCM) and other analytical methods provide a point estimate of average vehicle delay for a specified lane group over a defined time period (e.g., peak hour). The estimated delay is a function of a number of factors, including geometrAy, signal timings, and approach volumes. Some of these factors, particularly, peak hour volume, can be considered to be random variable, and therefore the distribution of intersection delay is a function of the distribution of these random factors. This paper presents findings of a study that addresses the variability in estimated HCM delay as a function of the variation of peak hour volumes. For protected movements, the distribution of delay is analytically determined as a function of the distribution of the peak hour volume and the HCM delay equation characteristics. A numerical method is proposed to find the distribution of delay for permitted movements for which capacity changes as a result of variability in the opposing volume. The proposed methods are demonstrated through application to a hypothetical intersection. The results indicate that when the degree of saturation for the average peak hour volume is not far from 1, the HCM point estimate of average delay is not sufficient for evaluating the quality of service or designing the intersection signal timing plan. For example, the results from the hypothetical intersection examined in this paper suggest that for a permitted left turn with an average degree of saturation of 0.77 and an average delay of (), there is approximately 20% probability that the lane group operates at a level of service of or worse (i.e., ).
Get full access to this article
View all available purchase options and get full access to this article.
References
Akcelik, R., and Rouphail, N. M. (1993). “Estimation of delays at traffic signals for variable demand conditions.” Transp. Res. Part B, 27(2), 109–131.
Colyar, J. D., and Rouphail, N. M. (2003). “Measured distributions of control delay on signalized arterials.” Transportation Research Record 1852, Transportation Research Board, Washington, DC, 1–9.
Fu, L., and Hellinga, B. (2000). “Delay variability at signalized intersections.” Transportation Research Record 1710, Transportation Research Board, Washington, DC, 215–221.
Hellinga, B., and Abdy, Z. (2008). “Signalized intersection analysis and design: implications of day-to-day variability in peak-hour volumes on delay.” J. Trans. Eng., 134(7), 307–318.
Khatib, Z. K., and Kyte, M. (2001). “Uncertainty in projecting level of service of signalized and unsignalized intersections.” 80th Annual Meeting of the Transportation Research Board, Washington, DC.
Levinson, H. S., Sullivan, D., and Bryson, R. W. (2006). “Effects of urban traffic volume variations on service levels.” 85th Annual Meeting of the Transportation Research Board, Washington, DC.
Noroozi, R., and Hellinga, B. (2011). “A method to estimate the distribution of average vehicle delay at signalized intersections.” 90th Annual Meeting of the Transportation Research Board, Washington, DC.
Olszewski, P. S. (1993). “Modeling of queue probability distribution at traffic signals.” Transportation and traffic theory, Koshi, M., ed., Elsevier, New York.
Olszewski, P. S. (1994). “Modeling probability distribution of delay at signalized intersections.” J. Adv. Trans., 28(3), 253–274.
Park, B., and Kamarajugadda, A. (2007). “Development and evaluation of a stochastic traffic signal optimization method.” Int. J. Sustainable Trans., 1(3), 193–207.
Park, B., and Li, C. (2011). “An analytical approach for estimation the highway capacity manual signalized intersection delay variability.” Comput. Aided Civ. Infrastruct. Eng., 26(4), 327–333.
Teply, S., and Evans, G. D. (1989). “Evaluation of the quality of signal progression by delay distributions.” Transportation Research Record 1225, Transportation Research Board, Washington, DC, 1–7.
Transportation Research Board. (2000). Highway capacity manual, Special Report, National Research Council, Washington, DC.
Information & Authors
Information
Published In
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Jun 4, 2010
Accepted: Mar 6, 2012
Published online: Mar 8, 2012
Published in print: Sep 1, 2012
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.