Patent GB-985214-A (GB)
Title: Traffic actuated control apparatus
IPC: G08G1/08
Filed: 1961-05-03
Abstract: 985, 214. Road traffic signals. LABORATORY FOR ELECTRONICS Inc. May 3, 1961 [May 9, 1960], No. 16099/61. Heading G4Q. A traffic control system for controlling the flow of traffic in one or more reversible lanes positioned between other lanes allocated to traffic flow in opposite directions, comprises measuring and comparing the traffic flow in both directions, and actuating signals in the reversible lanes,to allocate these lanes to one or other of the flow directions, depending on the relative traffic flows measured. A section of three lane road RY, Fig. 1, is provided with inbound traffic detectors ID, IDD and outbound traffic detectors, OD, ODD. Detectors ID,OD are linked with selectors ICS,OCS respectively which measure the inbound and outbound traffic. The detectors IDD and ODD are connected to a selector DS which links either detectors IDD, ID or detectors ODD,OD depending on whether the centre lane is being allocated to inbound or outbound traffic. Selector DS is also connected to master lane changer MLC which is linked to a local lane changer LLC, the latter operating traffic signals indicating the allocation of the central lane. In a modification, Fig. 6 (not shown) the centre lane detectors are replaced by a single bidirectional detector which is linked with either Selector ICS or OCS depending on the direction of travel of a vehicle crossing the detector. In an alternative form, Fig. 9 (not shown) two adjacent interior lanes of a multi-lane roadway serving bidirectional traffic are individually controlled so that the reversible lanes are positively allocated to one direction of traffic or the other, except during transition of one or both lanes. The incoming and outgoing traffic is measured by selectors ICS,OCS which provide outputs at one of the six levels AI. . . . FI,AO.... FO depending on the number of vehicles measured in the measuring interval. The outputs from ICS, OCS are compared in unit MC which produces outputs on either, both or neither of loads IG, OG depending on the relative output levels from selectors ICS,OCS. The signals on IG, OG are fed to unit MLC and energize combinations of the leads MIG, MOG, MCL which control a cyclic switch providing an operating cycle for signals allocating the lane L2 either to inbound or outbound traffic. With equal inbound and outbound traffic, both IG and OG are energized, the cyclic switch is in a rest position, and red signals IRS, ORS are illuminated in prohibiting use in either direction. Alternatively, a switch may be actuated to give flashing yellow signals in both directions, indicating that the central lane may be used for overtaking in either direction. If the inbound traffic increases two or more levels above the outbound, signals are transmitted from MC stepping the cyclic switch into a rest position giving a green signal IGS allocating the lane L2 to inbound traffic. At the same time detector IDD is coupled to detector ID by a signal over GI. Should the inbound and outbound traffic again become equal, signals are transmitted which cause the cyclic switch step on, giving yellow signal IYS followed by a red IRS to the inbound traffic,and detector IDD is disconnected from ID. An increase in outbound traffic above the inbound would similarly operate the cyclic switch to give a green signal OGS to outbound traffic, and couple detectors ODD and OD. Peak traffic conditions may be simulated by the actuation of switches. Specification 674, 590 is referred to.