EFFECT OF PLANTING IN MEDIAN STRIP ON NIGHT-VISIBILITY DISTANCES
STUDIES WERE INITIATED TO DETERMINE THE DEGREE TO WHICH MEDIAN PLANTING MIGHT BE ADVISABLE AS A PREREQUISITE FOR ENCOURAGING ALL DRIVERS TO USE THEIR HIGH BEAMS. DRIVERS SHOULD BE ENCOURAGED TO USE HIGH BEAMS BECAUSE OF THE INCREASED SEEING DISTANCE OBTAINED IN HIGH-SPEED DRIVING ON THE NEW JERSEY TURNPIKE. THE WIDTH OF THE MEDIAN ON THE TURNPIKE IS SUFFICIENT TO MINIMIZE THE EFFECTS OF HEADLIGHT GLARE, BEING 26 FEET THROUGHOUT MOST OF ITS LENGTH. SEVERAL PLANTING PATTERNS WERE DEVELOPED BY THE TURNPIKE ENGINEERING STAFF. DESIGN AIMS INCLUDED THE USE OF A MINIMUM NUMBER OF TREES, REASONABLE EASE IN MOWING GRASSED AREAS AND AVOIDANCE OF A HEDGE EFFECT. PLANTING PATTERNS WERE TESTED. SCRUB CEDAR TREES WERE USED TO SIMULATE PLANTING, EACH TREE BEING WEDGED INTO A CONCRETE BUILDING BLOCK AND TRIMMED TO A UNIFORM HEIGHT OF 5 FEET 6 INCHES. TEST RESULTS SHOW THAT AS MUCH AS 50 PERCENT SEEING DISTANCE CAN BE EXPECTED WITH TREES PLANTED AS IN THIS TRIAL. FURTHER TESTS ARE BEING CONDUCTED TO TAKE INTO ACCOUNT PROBLEMS OF LINE AND GRADE.
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Supplemental Notes:
- No 89, pp 16-20, 1 FIG, 2 TAB. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
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Authors:
- Ricker, Edmund R
- Roper, Val J
- Publication Date: 1954
Media Info
- Media Type: Digital/other
- Monograph Title: Night visibility
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Serial:
- Highway Research Board Bulletin
- Issue Number: 89
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Glare; Headlamps; Height; High beamed headlamps; Medians; Night visibility; Planting; Sight distance
- Old TRIS Terms: High beamed headlights; Median plantings
- Subject Areas: Highways; Safety and Human Factors;
Filing Info
- Accession Number: 00220412
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Apr 21 1994 12:00AM