LIMITING FAR-SIDE GREENS REDUCES ACCIDENTS AT THREE-LEVEL INTERCHANGE
REPORTABLE RIGHT-ANGLE ACCIDENTS AT A COMPLEX, THREE-LEVEL DIAMOND INTERCHANGE IN SUBURBAN MILWAUKEE HAVE BEEN SUBSTANTIALLY REDUCED BY REPLACING ALL FAR-SIDE GREEN INDICATIONS--BOTH LEFT-TURN AND THROUGH--WITH DISTANCE- LIMITED, OPTICALLY PROGRAMMED SIGNAL HEADS. THE SIGNALS WERE PROGRAMMED, OR MASKED, BY OPENING THE BACK AND VIEWING THE INTERSECTIONS PROJECTED ON ITS CURVED REAR LENS. PRESSURE- SENSITIVE ALUMINIM TAPE WAS USED TO COVER THE AREA OF THE INTERSECTION IMAGE WHERE THE SIGNAL WAS NOT TO BE VISIBLE. VIRTUALLY ALL MASKING WAS DONE TO LIMIT LONGITUDINAL VISION. SINCE IT IS ADVISABLE TO PLACE DISTANCE-LIMITED SIGNALS AS HIGH AS POSSIBLE, THIS WAS DONE AND THE ONLY DIFFICULTY ENCOUNTERED WAS COMPLAINTS BY TRUCK OR BUS DRIVERS THAT THEY COULDN'T SEE THE FAR-SIDE INTERSECTION GREENS UNTIL THEY WERE QUITE CLOSE TO THEM. SUPPLEMENTARY LEFT-TURN SIGNALS WERE SET UP PART WAY THROUGH EACH TURN TO CONFIRM TO THE MOTORIST THAT HE WAS PROCEEDING PROPERLY. PRIOR TO INSTALLATION OF THESE SIGNALS ACCIDENTS AVERAGED 4 PER MO. THIS FIGURE HAS CONTINUOUSLY DECREASED AND WAS 1.5 PER MO. AT THE TIME THIS REPORT WAS MADE.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/oclc/1606878
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Authors:
- Shebesta, H
- Publication Date: 1973-1
Media Info
- Pagination: p. 52-3
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Serial:
- Public Works
- Volume: 104
- Issue Number: 1
- Publisher: Hanley Wood
- ISSN: 0033-3840
- Serial URL: http://www.pwmag.com
Subject/Index Terms
- TRT Terms: Crash rates; Diamond interchanges; Left turns; Optical properties; Prevention; Safety; Traffic signals; Vision
- Uncontrolled Terms: Longitudinal
- Old TRIS Terms: Tapes /metallic and elastomeric/
- Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors; Security and Emergencies;
Filing Info
- Accession Number: 00226746
- Record Type: Publication
- Files: TRIS
- Created Date: Apr 20 1974 12:00AM