The CORQ corridor traffic prediction model has been overhauled to produce the current version CORQ2, for pre-evaluating peak-period traffic management schemes. CORQ2 has a pre-processor which allows the user to simply input basic network characteristics and counts of existing flows and queues, along with the trip traces of a sample of the network users. The network parameters include: link type, such as freeway section, progressed or unco-ordinated signalized arterial; capacity; space for queueing; and free flow travel time. The preprocessor uses the information that it is provided with to calculate a set of time-varying origin-destination (O-D) demand patterns for the peak period. CORQ2 then uses these O-D's to test the effects of any proposed traffic management scenarios, such as a given combination of time-varying ramp meters and closures, on the pattern of flows, queues and delays in the network. CORQ2 also has a graphics output package, which illustrates snapshots of the flows and queues in the network at typically 15-minute intervals. It plots links with low, intermediate and high volume/capacity ratios differently, either in color of black and white. The paper describes the background to the development of assignment-based corridor models which incorporate queueing, and the development and operation of CORQ2. It highlights the graphical output and uses for it, and gives a somewhat frank discussion of the evolved status quo of corridor modelling. (A)
Samenvatting