EFFECT OF WEATHER AND ROAD CONDITIONS ON SPEEDS

RESULTS ARE PRESENTED OF A SURVEY CARRIED OUT LAST WINTER ON THE EFFECT OF WEATHER AND ROAD CONDITIONS ON OPERATING SPEEDS. APPROXIMATELY 11,500 SPEED MEASUREMENTS WERE COLLECTED BY RECORDING THE NUMBER PLATE AND BY MEANS OF RADAR. THE FACTORS TAKEN INTO CONSIDERATION WERE THE WET OR DRY CONDITIONS OF THE ROAD SURFACE, PRESENCE OF ICE AND SNOW ON THE SHOULDERS OF THE ROAD, AND WINTER MAINTENANCE MEASURES (GRITTING, SPREADING OF SAND-SALT MIXTURES, REMOVAL OF SLUDGE AND SNOW). RESULTS SHOWED THAT: (1) SPEEDS TEND TO BE LOWER ON WET ROAD SURFACES, PARTICULARLY ON METALLED ROADS; (2) ICE AND SNOW ON SHOULDERS DO NOT AFFECT SPEED IF THE HIGHWAY IS DRY; (3) THE PRESENCE OF A LAYER OF ICE ON THE ROAD REDUCES SPEED MARKEDLY; (4) A LOOSE 1 TO 3 CM-THICK LAYER OF SNOW AND SLUDGE IS THE MOST IMPORTANT FACTOR IN REDUCING SPEED, (5) GRITTING HAS NO EFFECT ON SPEED, (6) THE SPREADING OF A SAND-SALT MIXTURE RESULTS IN A 4 TO 6% INCREASE IN SPEED, AND (7) A RUTTED ROAD SURFACE WHICH IS SNOW COVERED CAN BE GREATLY IMPROVED BY LEVELLING. /TRRL/

• Authors:
  • Maeki, S
• Publication Date: 1972

Language

• English

Media Info

• Features: Figures;
• Pagination: p. 353-60
• Serial:
  • Tielehti, Helsinki /Finland/
  • Issue Number: 8

Subject/Index Terms

• TRT Terms: Cold weather; Data collection; Dryness; Frost damage; Moisture content; Operations; Ruts (Pavements); Snow and ice control; Speed; Studies; Surveys; Traffic speed; Weather
• Uncontrolled Terms: Dry conditions; Rut; Wet conditions
• Old TRIS Terms: Speed studies
• Subject Areas: Administration and Management; Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226963
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: TRIS
• Created Date: Jan 11 1974 12:00AM