A NEW TECHNIQUE FOR ESTIMATING MOTORWAY SPEEDS AND SOME RESULTS OBTAINED UNDER THE EMERGENCY 50 MPH SPEED LIMIT

THE EMERGENCY 50 MPH SPEED LIMIT IN THE UK CAME INTO FORCE ON DECEMBER 8, 1973 IN RESPONSE TO A NATIONAL OIL SHORTAGE. SINCE THAT TIME, A NUMBER OF TEST RUNS HAVE BEEN MADE ALONG A 43 MILE LENGTH OF ROUTE CONSISTING OF THE WHOLE OF M2 IN KENT AND AN ADJOINING DUAL-CARRIAGEWAY SECTION OF A2 TO DETERMINE THE EFFECT OF THE LIMIT ON AVERAGE JOURNEY SPEEDS. THE METHOD REQUIRES THE DRIVER (OR AN OBSERVER) TO RECORD ON EACH RUN THE NUMBERS OF OVERTAKING AND OVERTAKEN VEHICLES, TOGETHER WITH THE JOURNEY TIME AND DISTANCE. THE RESULTS POINT TO AN INCREASE IN SPACE-MEAN SPEED FROM ABOUT 48 MPH IN MID-DECEMBER, 1973 TO A LEVEL OF ABOUT 53 MPH AT THE TIME THE LIMIT WAS LIFTED, DURING GOOD WEATHER CONDITIONS. THIS IMPLIES THAT BY APRIL, 1974 MOST VEHICLES WERE EXCEEDING THE TEMPORARY LIMIT AT NEARLY ALL POINTS ON THE ROUTE. /AUTHOR/

  • Availability:
  • Corporate Authors:

    Institution of Highway Engineers

    27 Earl Street
    Maidstone, Kent ME14 1PE,   England 
  • Authors:
    • WRIGHT, C C
  • Publication Date: 1974-10

Media Info

  • Features: Figures; References;
  • Pagination: p. 32-35
  • Serial:
    • Highway Engineer
    • Volume: 21
    • Issue Number: 10
    • Publisher: Whitehall Press Limited
    • ISSN: 0306-6452

Subject/Index Terms

Filing Info

  • Accession Number: 00083270
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Apr 8 1975 12:00AM