Determination of reliability indices for congestion on urban arterial streets

Motorists tend to accept certain levels of delay during peak traffic conditions, but become increasingly agitated when the travel times increase unpredictably due to incidents on roadways. The objective of this thesis is to develop a reliability index quantifying the spatial and temporal distribution of traffic congestion on urban arterial streets. Delays caused due to recurrent and non-recurrent congestion need to be differentiated. Two approaches for estimating road network reliability are proposed to quantify delays due to recurrent and non-recurrent congestion. These indices are expressed as functions of operating speed and travel time respectively. A case study using urban arterial streets in the Las Vegas Metropolitan area is presented to illustrate the methodology and applications of the proposed reliability indices. These indices are valuable for transportation managers for system management and for travelers for making decisions related to, trip choices such as route, mode and travel time.