01126680

Component

Nonrecurring congestion creates significant delay on freeways in urban areas, lending importance to the study of facility reliability. In locations where traffic detectors record and archive data, approximate probability distributions for travel speed can be determined from historical data; however, the coverage of detectors is not always complete, and many regions have not deployed such infrastructure. This paper describes procedures for estimating such distributions in the absence of this data, considering both supply-side factors (reductions in capacity due to events such as incidents or poor weather) and demand-side factors (such as daily variation in travel activity). Using data from the Dallas metropolitan area, the supply-side analysis identifies probability distributions that fit observed speed data, and develops regression models for estimating their parameters. For cases in which data is available on demand variations, a demand-side procedure is presented for refining the analysis to account for this source of uncertainty.

01120148

09-3648

English

15p

2009

Transportation Research Board 88th Annual Meeting

DVD

Figures (2) ; References (36) ; Tables (3)

Highway capacity; Highway facilities; Incident detection; Operations; Traffic data; Traffic delays; Traffic distribution; Traffic speed; Travel demand; Uncertainty

Highways; Operations and Traffic Management; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2009 Paper #09-3648

TRIS, TRB

Jan 30 2009 8:04PM