Project: Braking: Commercial Vehicle Tractor/Trailer Pressure Control

Reference: S290B/VD

Last update: 03/12/2003 11:38:04


The objectives were to study vehicles over a range of threshold pressures permitted by the compatibility corridors of ECE Regulation 13 (R.13) and develop proven proposals that would enhance braking performance and stability and reduce maintenance costs to the operating industry. The basic methodology was to use an articulated vehicle with variable brake threshold pressures and assess the dynamic and static braking performance and lining wear characteristics over the range of braking system threshold pressures permitted by Regulation 13. The tests consisted of using a roller brake tester at a Vehicle Inspectorate (VI) Heavy Goods Vehicle Testing Station (HGVTS), dynamic performance tests on the TRL test track and road trials involving high mileage travelling around a predetermined test route.


For several years, reports of premature in-service brake performance loss and high maintenance costs have brought the suitability of the currently required compatibility curves into question. This report presents a summary of work on a project to assess the effects of brake threshold pressures on articulated heavy vehicle braking performance.


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

Contract details

Cost to the Department: £214,980.00

Actual start date: 03 January 1995

Actual completion date: 02 January 1997


PR/SE/205/96. Commercial Vehicle Tractor/Trailer Pressure Control - Final Report
Author: TRL Ltd
Publication date: 02/01/1997
Source: Contact:

Summary of results

  1. The objectives were fully met with the exception of the assessment of the regulated brake compatibility corridors. This did not affect the project as changes in international braking requirements will require further research. It is likely that the corridor assessments will be different from those that would have been achieved during this phase.

    The detailed project results are contained in the reports, which were delivered in a timely manner.