Project: HGV Spray: Test Methods and Standards

Reference: S190B/VE

Last update: 03/12/2003 12:59:19


The advantages and disadvantages of such possible developments will need to be compared with those of other possible approaches to spray control - e.g. using freely draining road surfaces such as porous asphalt, and wet-weather speed limits. To assist in this task, Vehicle Standards Engineering Division of DOT asked TRL to undertake a simple analysis of the likely costs and effectiveness of alternative approaches to spray control. The study was to use only information already available, and make simplifying assumptions where necessary, so as to allow an initial, broad comparison to be made between possible approaches to spray control.


Spray from lorries in wet weather is a severe nuisance to car drivers. Its contribution to accidents is difficult to assess but a TRL study (Savill, 1994) asked police officers to judge the contribution of spray to the wet-weather injury accidents they were reporting on. It estimated that spray plays a part in between 131 and 552 injury accidents each year on motorways and A(M) roads in Britain at an annual cost of between £7 and £29 million.

In response to growing concern about lorry spray, regulations were made to require many goods vehicles must be fitted with BS approved spray control equipment. Future developments in spray control legislation might include adding new or improved devices to the list of BS/EC approved designs. Alternatively, a whole-vehicle performance standard might replace, or supplement, the design standard. Such an approach could encourage aerodynamic solutions to spray control which are difficult to specify in a design standard.


TRL Limited
Crowthorne House, Nine Mile Ride, Wokingham, Berkshire, RG40 3GA
+44 (0)1344 773131

Contract details

Cost to the Department: £747,390.00

Actual start date: 01 March 1992

Actual completion date: 31 May 1997


PR/SE/136/96. Cost Effectiveness of Alternative Approaches to Spray Control
Author: TRL Ltd
Publication date: 01/05/1997
Source: Contact:

PR/SE/147/96. Spray from Road Vehicles. A Test Method and Results for a Range of Vehicle Types
Author: TRL Ltd
Publication date: 01/05/1997
Source: Contact:

Summary of results

  1. This project produced a range of recommendations for reducing the problems of spray from lorries in wet weather, along with a spray test method for a range of vehicle types.