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Online Traffic Model Correction from Sensor Counts

IP.com Disclosure Number: IPCOM000080098D
Original Publication Date: 1973-Oct-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Cherrill, JG: AUTHOR [+2]

Abstract

A traffic control system employs a model which shows, for each road intersection, the predicted vehicle arrivals over each of a number of periods, for example, 32 four-second periods. The vehicle arrival figures are used, in conjunction with traffic light pattern indications to develop vehicle queue figures, and these are utilized to optimize the traffic light patterns to minimize delay at each intersection.

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Online Traffic Model Correction from Sensor Counts

A traffic control system employs a model which shows, for each road intersection, the predicted vehicle arrivals over each of a number of periods, for example, 32 four-second periods. The vehicle arrival figures are used, in conjunction with traffic light pattern indications to develop vehicle queue figures, and these are utilized to optimize the traffic light patterns to minimize delay at each intersection.

The model is constructed by projecting predicted patterns of vehicles leaving the intersections, to generate predicted vehicle arrivals at downstream intersections. When used in an online mode, the predicted vehicle arrival figures for the first few periods of each intersection arrival pattern are continuously replaced, by predicted vehicle arrival figures obtained from vehicle sensors located upstream of the intersections.

The arrival figures derived from the sensors are, of course, the most accurate, and the accuracy of each predicted arrival pattern decreases as the prediction period increases.

In order to compensate for this lowered accuracy for the long-term portions of the arrival predictions, the sensor counts, before replacing the corresponding predicted arrival figures, are compared with these figures to produce a flow correction factor. This correction factor represents the actual average flow of vehicles approaching an intersection over the predicted average flow of these vehicles. The predictions...