Browse Prior Art Database

Optimization of Vehicular Traffic Flow

IP.com Disclosure Number: IPCOM000079786D
Original Publication Date: 1973-Sep-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 26K

Publishing Venue

IBM

Related People

Markarian, HM: AUTHOR [+2]

Abstract

This is a method of optimizing traffic flow through a subnetwork of roadways and intersections. A single-cycle length is first calculated on which all traffic signals in the subnetwork are operated. A group of green splits are then calculated for operation of the traffic signals in the subnetwork. The maximum bandwidth for each roadway in the subnetwork is calculated and then optimum offset times are calculated for the signals on each roadway in the subnetwork. A group of Performance Indices is then calculated, from which the signals of the subnetwork to be controlled are synchronized by the offsets corresponding to the maximum Performance Index.

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Optimization of Vehicular Traffic Flow

This is a method of optimizing traffic flow through a subnetwork of roadways and intersections. A single-cycle length is first calculated on which all traffic signals in the subnetwork are operated. A group of green splits are then calculated for operation of the traffic signals in the subnetwork. The maximum bandwidth for each roadway in the subnetwork is calculated and then optimum offset times are calculated for the signals on each roadway in the subnetwork. A group of Performance Indices is then calculated, from which the signals of the subnetwork to be controlled are synchronized by the offsets corresponding to the maximum Performance Index.

The cycle time corresponding to each intersection is calculated according to the Webster equation, based on traffic flow data from traffic sensors placed in each of the roadways and measuring the number of vehicles passing the sensors in a specific time. The longest of the cycle times thus computed is chosen as the critical cycle time, on which intersections will be operated.

The green split times are based on traffic flow data derived from the traffic flow sensors, the selected critical cycle time, and the length of time that the amber signal is displayed.

An initial bandwidth is drawn from the intersection with the minimum green split time. At each intersection along a roadway interference can occur on either the left or right of the initial bandwidth, depending on how offsets are selected. The choice of the initial bandwidth assures that interference cannot occur on both sides simultaneously. The interferences are computed for each intersection by initially off-setting each s...