"RIFLE SHOT ACCURACY" OF OPTICALLY PROGRAMMED SIGNALS ARE DISIGNED FOR BETTER TRAFFIC CONTROL

THE ELGIN DISTRICT OF ILLINOIS DIVISION OF HIGHWAYS IS INSTALLING OPTICAL SIGNALS WHOSE BEAMS CAN BE CONFINED WITH VIRTUAL RIFLE SHOT ACCURACY TO THE LANES OR ROADWAY AREAS FOR WHICH THE TRAFFIC ENGINEERS AIM. TO DRIVERS NOT IN THE "TARGET" AREA THE LIGHTS SIMPLY APPEAR NOT TO BE IN USE. THE ESSENTIAL PART OF THE LIGHTS IS AN INCREMENTAL LENS SEALED IN ACRYLIC FOR ITS PROTECTION. JUST BEHIND THE LENS IS A CONVEX GLASS ELEMENT CALLED THE OPTICAL LIMITER. THE PORTION OF THE IMAGE THAT WILL BE BLOCKED OUT IS DONE WITH A SPECIAL TAPE. THE OPTICAL SIGNALS ARE BEING BASICALLY USED FOR LEFT TURNS AND TO KEEP THE THROUGH TRAFFIC MOVING WITHOUT HESITATION BY HIDING THE TURN INDICATION FROM THE THROUGH TRAFFIC. THESE SIGNALS SEEM TO CLARIFY THE MOVEMENTS REQUIRED OF TRAFFIC AND DOES LIMIT DRIVER ERROR.

• Supplemental Notes:
  • Vol 6, No 2, PP 18 - 19, 2 PHOT
• Publication Date: 1970-3

Media Info

• Serial:
  • IMSA Signal Magazine
  • Publisher: International Municipal Signal Association

Subject/Index Terms

• TRT Terms: Indicators (Instruments); Through traffic; Traffic control; Traffic flow; Traffic signal indications; Traffic signals; Turning lanes
• Old TRIS Terms: Traffic control systems
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00225742
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM