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https://nap.nationalacademies.org/catalog/27432/critical-issues-in-transportation-for-2024-and-beyond

NEW TRAFFIC CONTROL SYSTEM STUDY IS UNDERWAY IN THE CITY OF ST. PAUL, MINNESOTA

THE OPTICOM EMERGENCY CONTROL SYSTEM IS A DEVICE THAT WILL REMOTLY CONTROL TRAFFIC SIGNAL CONTROLLED INTERSECTIONS TO PERMIT EMERGENCY VEHICLES TO ENTER THE SIGNALIZED INTERSECTION ON A GREEN LIGHT. THE DETECTOR ASSEMBLY CONSISTS OF A PHOTO-ELECTRIC DEVICE CONNECTED TO A PREAMPLIFIER. THE DETECTOR IS SENSITIVE TO THE RED AND INFRA RED SPECTRUM DEVELOPED BY THE PULSING LIGHT OF THE EMERGENCY VEHICLE. THE PREAMPLIFIER IS DESIGNED TO RECOGNIZE THE PULSE RATE EMITTED BY THE LIGHT SOURCE ON THE EMERGENCY VEHICLE. AFTER THE DETECTION HAS PICKED UP THE LIGHT SOURCE IN THE AMPLIFIER, THE SIGNAL IS DELIVERED TO THE PHASE SELECTOR WHICH IS MOUNTED ON THE TRAFFIC SIGNAL CONTROLLER. ONCE A DECISION IS MADE THAT THE ON-COMING SIGNAL IS AN EMERGENCY VEHICLE, A VOLTAGE IS DEVELOPED WHICH CLOSES A RELAY IN THE PHASE SELECTOR. THE PHASE SELECTOR THEN DETERMINES THE CONDITION OF THE TRAFFIC SIGNAL. THE PHASE SELECTOR MONITORS THE GREEN AND AMBER FOR EACH PHASE AND INITIATES APPROPRIATE ACTIONS TO CAUSE THE CONTROLLER TO CYCLE INTO GREEN IN FAVOR OF THE APPROACHING VEHICLE AND HOLD GREEN UNTIL THE EMERGENCY VEHICLE HAS CLEARED THE INTERSECTION. THE CITY OF ST. PAUL, MINNESOTA, HAS INSTALLED OPTICOM AT 28 INTERSECTIONS TO ATTEMPT TO REDUCE THE NUMBER OF ACCIDENTS INVOLVING FIRE DEPARTMENT VEHICLES AT THESE INTERSECTIONS.

  • Supplemental Notes:
    • Vol 6, No 2, PP 14 - 15, 4 PHOT
  • Authors:
    • Ameter, H E
  • Publication Date: 1970-3

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  • Accession Number: 00225740
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 27 1970 12:00AM