A method is described for generating origin-destination (OD) matrices for the subset of drivers who are likely to divert in response to any changes to the traffic network, such as ramp metering for freeways. These ODs are generated automatically from responses to survey questionnaires handed out at strategic points in the network. The responses are factored up to represent 100% of the observed flow on critical links. The procedure also preloads onto the network any link volumes that are not represented by factored survey responses, and are presumably insensitive to any control schemes that might be considered. Preloading of the less sensitive flows, rather than the existing procedure of creating and assigning pseudo-ODs, should reduce the work required of the analyst and lead to improved predictions of flows and queues.
Abstract