The AWAM system can estimate the time a device was present in the range of a reader by looking at the timespan between the first and last time a device was read. This measurement can be described as reader passage time and can be used as a surrogate value for intersection delay. Note that the passage time resolution is dependent on the Address Resend Threshold parameter on the AWAM field device. Lower Address Resend Thresholds will allow for finer resolution of the passage time.

To estimate the passage time for a reader, select a reader to calculate passage time for and then a combination of upstream and/or downstream readers that correspond to the direction of travel you want to measure. The diagram to the right illustrates a sample passage time calculation scenario. The maximum allowable passage time should also be specified to limit travelers who are stationary at a reader for an extended amount of time.