00636279

Component

http://onlinepubs.trb.org...trr/1993/1387/1387-026.pdf

https://scholar.google.co...uchi&publication_year=1993

Reduced visibility for drivers due to snow and its relationship to safe highway operations have been major concerns of road authorities. Visibility even in calm weather is reduced by airborne snow in clouds created by moving vehicles. A study was conducted using a reflector-type visibility sensor placed on a road median to observe the reduction of visibility. A snow-particle counter was mounted on the roof of a vehicle to measure the size of entrained airborne snow particles while driving through a snow cloud. As the temperature drops, cohesion of snow particles decreases and they are easily blown up from the road surface. Visual range was found to change from hundreds to tens of meters in a short time when a snow cloud formed. Collector snow fences reduce the dissipation of vehicle-generated snow clouds on highways. Poor visibility continued longer in sections with snow fences than in areas with no fences. The number of small snow particles is greater in a vehicle-generated snow cloud than in wind-blown snow. Large vehicles cause large snow clouds, and the extent of a snow cloud depends on vehicle size. Snow particles in a vehicle wake are lifted about to the level of the vehicle's roof. In contrast, average visibility is improved and fluctuation of visibility on a highway is mitigated with collector snow fences in blowing snow conditions. However, a snow fence leads to decreased visibility in snow clouds generated by vehicles. The characteristics of visibility in blowing snow and in vehicle-generated snow clouds on highways are presented.

This paper appears in Transportation Research Record No. 1387, Snow Removal and Ice Control Technology; Papers presented at the 3rd International Symposium on Snow Removal and Ice Control Technology, September 14-18, 1992, Minneapolis, Minnesota. 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

01495762

English

p. 178-182

1993

Transportation Research Record

Third International Symposium on Snow Removal and Ice Control Technology

0309054583

Figures (10) ; Photos (1) ; References (5)

Clouds; Cohesion; Grain size (Geology); Measurement; Motion; Motor vehicles; Snow; Snow fences; Vehicle size; Visibility; Visibility distance; Wind

Moving vehicles; Reduced visibility; Reduction (Decrease)

Highways; Maintenance and Preservation; Safety and Human Factors; I62: Winter Maintenance; I83: Accidents and the Human Factor

TRIS, TRB

Sep 3 1993 12:00AM

• ABRASIVE AIR BLAST SYSTEM FOR DISBONDING ICE AND SNOW FROM PAVEMENT
• AN APPROACH TO THE DESIGN OF TREATMENTS TO PREVENT SNOWDRIFTING ON HIGHWAYS
• ANALYTICAL MODEL FOR TWO-STAGE ROTARY SNOWPLOWS
• ANTI-ICING ACTIVITIES IN FINLAND: FIELD TESTS WITH LIQUID AND PREWETTED CHEMICALS
• BRAKING TRACTION ON SANDED ICE
• COASTAL INFLUENCE ON WINTER ROAD-SURFACE TEMPERATURES IN THE COUNTY OF DEVON, ENGLAND
• COST-EFFECTIVE SNOW AND ICE CONTROL FOR THE 1990S
• CURRENT STATUS OF U.S. ANTI-ICING TECHNOLOGY DEVELOPMENT
• DEICING OF ROADS IN NORWAY WITH BRINE
• DESCRIPTION AND VERIFICATION OF A ROAD ICE PREDICTION MODEL
• DESCRIPTION OF A LOCAL CLIMATOLOGICAL MODEL FOR IMPROVEMENT OF WINTER ROAD SURVEYS
• DETAILED WEATHER PREDICTION SYSTEM FOR SNOW AND ICE CONTROL
• ENVIRONMENTAL EFFECTS OF ALTERNATIVE DEICERS: REVIEW AND ASSESSMENT METHOD FOR CALCIUM MAGNESIUM ACETATE BIOCHEMICAL OXYGEN DEMAND APPLIED TO ILLINOIS EXAMPLE CASE
• FIELD TESTING OF NEW CUTTING EDGES FOR ICE REMOVAL FROM PAVEMENTS
• FRENSOR: A NEW SMART PAVEMENT SENSOR
• GOALS AND METHODS OF WINTER MAINTENANCE IN FINLAND
• INFLUENCE OF REGULATION OF STUDDED TIRE USE IN HOKKAIDO, JAPAN
• METHODS AND MATERIALS FOR SNOW AND ICE CONTROL ON ROADS AND RUNWAYS: MINSALT PROJECT
• METHODS AND REASONS FOR CUTTING USE OF SALT IN FINLAND
• NEW IDEAS AND EQUIPMENT FOR WINTER MAINTENANCE IN FINLAND
• ON THE PREDICTION OF ROAD CONDITIONS BY A COMBINED ROAD LAYER-ATMOSPHERIC MODEL IN WINTER
• PERFORMANCE EVALUATION OF PAVEMENT WITH DEICING MATERIALS
• PROPOSAL FOR NEW WINTER ROAD MAINTENANCE STRATEGY: MINSALT
• QUALITY, QUANTITY, AND AVAILABILITY OF WEST VIRGINIA OIL AND GAS WELL BRINES FOR HIGHWAY DEICING PURPOSES
• ROAD WEATHER INFORMATION SYSTEMS: WHAT ARE THEY AND WHAT CAN THEY DO FOR YOU?
• ROAD WEATHER SERVICE SYSTEM IN FINLAND AND SAVINGS IN DRIVING COSTS
• SNOW REMOVAL AND ICE CONTROL TECHNOLOGY ON SWISS HIGHWAYS
• SODIUM SALTS OF CARBOXYLIC ACIDS AS ALTERNATIVE DEICERS
• TRADE-OFF ANALYSIS OF NONENVIRONMENTAL EFFECTS OF ALTERNATIVE DEICERS: AN ILLINOIS CASE STUDY
• TRAFFIC VOLUME REDUCTIONS DUE TO WINTER STORM CONDITIONS
• TRAPPING EFFICIENCY OF SNOW FENCES AND IMPLICATIONS FOR SYSTEM DESIGN
• TRIALS OF CALCIUM MAGNESIUM ACETATE DEICER ON HIGHWAYS IN ONTARIO
• VARIATION IN MOTORIST VISUAL RANGE MEASURED BY VEHICLE-MOUNTED SENSOR