TRAFFIC CONTROL BY SOUND

Hawera Star, Volume XLVII, 9 June 1928, Page 15

TRAFFIC CONTROL BY SOUND

Traffic device® are udreaay legion, bat one of decided novelty has just nei » reported from Baltimore. Its outstanding feature is that it is controlled oy sound waves, and it is intended to protect crossings on country highways or m suomban areas away from eon geste l obstructs. Cross-rug signals controlled by timing mechanism are api to create endn-ss coiigesuor because of their cons'-ant interruptions to the streams of trafnc moving at thigh speed along ttie main road. The- interference comes at regular intervals, regardless of the state of traffic, aud holds up progress on the mam road even when there in an entire absence of vehicles on the intersecting by-road. The new ; uevive, known ns t»he Adler i ,s ctfssi”r»ou to obviate these interferences with the principal flow of traffic. Thu device involves the use of a threecolour automatic signal, controlled f-y the actual traffic movement along ine minor thoroughfare. Suspended at the ciosiing, the signal normally displays the gieen light for travel on the mam highway and the red light lor vehicles in the intersecting channel. 1 hose lights remain fixed until an itutomdoue approaches along the minor load. I airing ihie red light the driver ci this car conies forward, at -slow speed. Near the coiner is placed a microphone, fixed to a post. To procure for himself a- clear I assage across the main channel, the motorist has only to sound his horn when he ;s close to the transmitter. Ihe vib rations thus caused are pie sod no by tuc microphone and cominuui'-ntwl bo the mechanism of the signal. Aciiiated -by these- vibrations, the mechanism shifts electrical ciircuis, and changes the lights on the main artery of travel, causing the green to give way to .amber, followed bv red. The same operation causes green to appear for rue cross road, permitting the motorist who .sounded the horn to- cross in safety. The new position of the lights remain lixecl for ten seconds, or for such cycle as may be -predetermined by adjustment. At the end of the cycle the lights are restored to normal, permitting the resumption of travel on the mam -road, and blocking the crosswise movement. The first installation of the new signal has been made by the Baltimore police department at a minor crossing in r outlying district.