Patent GB-1194374-A (GB)
Title: Improvements in or relating to Traffic Control Apparatus
Inventor: VILLEMAIN CHARLES
IPC: G08G1/07
Filed: 1967-06-26
Abstract: 1,194,374. Traffic signals. SOC. D'ETUDES TECHNIQUES ET D'ENTREPRISES GENERALES. 26 June, 1967 [24 June, 1966], No. 29473/67. Heading G4F and G4Q. [Also in Division E1 and F4] Traffic signals are disposed along a road, river or canal between two intrsections, each signal being visible only to vehicles &c. in a limited section of the road &c., the signals are operated in sequence so that a green phase travels along the road &c. at a speed depending on the operation of the intersection traffic signals. A vehicle &c. which keeps in step with this green phase will not be halted at the next intersection signal. The guiding signals preferably show a green-amber-red sequence, but the amber may be omitted; they may flash. The instants when the guiding signals change is normally controlled by a programme on punched tape (Fig. 12, not shown), sensed by three separate pins (P1-P3) for each signal, each pin controlling one colour. Counters may be provided to switch the guiding signals to red when the number of vehicles &c. in a given section of road &c. exceeds a predetermined number, or to indicate the number of parking spaces available at the side of the road. The guiding lights may also be used to control traffic which merges at a junction or diverges from a junction. In the former case the length or speed of the green phase of the lights after the junction will be double that of the roads or lanes approaching the junction; the lights in the approaches should be out of phase with one another. In the case of a divergence the lights in the outgoing roads or lanes are adjusted in accordance with the relative proportion of traffic using them. Construction of guiding lights (Fig. 7).-The lights are mounted in a housing 10 on the ground or recessed into the road, the housing containing green 100, amber 101 and red 102 lights, with distribution boxes 103, 104 at the ends. The upper surface is bowed to allow water to run off. Each section 100-102 consists of a coloured lamp (105 in Fig. 8, not shown) embedded in a block of glass. The surface of the latter is angled in steps (Fig. 10, not shown) so that rays emitted from the lamp at an angle to the vertical are concentrated into a narrow lobe (Fig. 9, not shown) which is visible to a driver only over a short length at a predetermined distance from the light. A small secondary lobe allows the light to be seen when the driver is level with it. Preferably every second or third light is caused to flash at a rate depending on the desired speed of the vehicles. Current is supplied to the lamps by a bus-bar on each side thereof. Alternative construction of guiding lights (Fig. 2).-A flat cable of insulating plastic, optionally containing reflective or luminescent material, serves as a dividing line for traffic lanes and contains the red, amber and green lights in a unit 210. The cable may be secured to the road by pins (Fig. 2A, not shown). The conductors may be laid in grooves (226) under a plate which contains the marking lines (224) for the traffic lanes (Fig. 2B, not shown). The invention is also applicable to aircraft or railway control and the control of vessels along canals or rivers.