The effect of de-icers on skid resistance and skidding accidents

The Highways Agency, in common with all UK highway authorities, has a duty to keep roads for which it is responsible free of ice and snow, Apart from saving lives and preventing injuries, using deicers costs the country much less than it would of the ice were ignored and accidents and the congestion that results, were allowed to happen. Even though surfaces treated with salt are unlikely to be as slippery as an icy surface, some road users are concerned that deicers can build up on road surfaces and might increase the risk of skidding accidents. To gain a better understanding of what these risks actually are, the Highways Agency commissioned TRL Limited to investigate the effects of deicing operations on skidding resistance and skidding accidents. Direct measurements of skidding resistance were made in winter conditions on two types of road surfacing treated with different types of deicer, including two with additives, in order to assess the physical effects. This included using the Highways Agency's Pavement Friction Tester to assess the effects at different speeds from 20-100 km/h in selected locations and a GripTester operated at 50 km/h to make a continuous assessment of the road. The measurements covered a range of conditions, including wet or dry surfaces and different residual salt levels. It was not possible to test the effect of a build-up of deicer and detritus during prolonged cold spells with little or no rainfall. In the second phase, accident statistics in the Stats19 database recorded for the trunk road network during the period 2002-2005 were analysed to assess whether there was any evidence to indicate that accident risks increased when the roads had been salted. This assessment included the potential influence of repeated deicing operations, relative risks at junctions and for vulnerable road users such as motorcyclists. The study was supported by seeking the views of maintaining agents to identify any anecdotal trends that might not be reflected in the injury accident statistics.

• Authors:
  • ROE, P G
  • CRINSON, L
  • EVANS, M
  • JORDAN, R
  • MARTIN, J
• Publication Date: 2008

Language

• English

Media Info

• Serial:
  • PUBLISHED CONFERENCE ARTICLE
  • Issue Number: 006

Subject/Index Terms

• TRT Terms: Arterial highways; Crash rates; Deicing; Hazards; Prevention; Risk assessment; Safety; Skid resistance; Skidding; Statistics
• Geographic Terms: United Kingdom
• ITRD Terms: 1661: Accident prevention; 1612: Accident rate; 2598: Deicing; 2748: Main road; 9150: Risk; 9129: Risk assessment; 3031: Skid resistance; 1645: Skidding; 6555: Statistics; 8119: United Kingdom
• Subject Areas: Data and Information Technology; Highways; Maintenance and Preservation; Pavements; Safety and Human Factors; Security and Emergencies; I23: Properties of Road Surfaces; I62: Winter Maintenance; I81: Accident Statistics; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 01104760
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Jul 17 2008 1:18PM