APPLICATION OF MONTE CARLO SIMULATION FOR DELAY ANALYSIS OF SIGNALIZED INTERSECTIONS

摘要

Capacity of signalized intersections is evaluated in terms of the ratio of demand flow rate to capacity, whereas Level of Service (LOS) is evaluated on the basis of control delay per vehicle (in seconds per vehicle). Control delay is the portion of the total delay attributed to traffic signal operation for signalized operations which includes initial deceleration delay, queue move-up time, stopped delay, and final acceleration delay. The Highway Capacity Manual (HCM) methods represent traffic flows with variables that reflect the flow dynamics. Unlike the empirical and analytical models, simulation models predict performance by stepping through time and across space, tracking events as the system state unfolds. Making a decision as to the adequacy of LOS based on a single parameter i.e., control delay may not be appropriate as control delay is a probabilistic quantity and a function of several variables indicated above that are also probabilistic quantities. A comparison of the LOS results in case of signalized intersections between HCM 1994 and HCM2000 methodologies is made in this paper using Monte Carlo simulation. The probability of achieving various levels of service is calculated using statistical principles. An analysis of the LOS results indicates that HCM2000 is more conservative when compared to HCM 1994.