Few systems matter more to roadworthiness than the brakes, and few attract more attention from DVSA. The DVSA Guide to maintaining roadworthiness (updated April 2025) expects a brake performance assessment at every safety inspection. This article explains the methods the guide accepts, how roller brake testing and an electronic braking performance monitoring system (EBPMS) fit together, and what each means for trailers and for HGVs.
What DVSA expects at every safety inspection
The guide expects every safety inspection to include a brake performance assessment using one of three methods:
- a roller brake test (RBT), preferably laden;
- a suitable EBPMS, which at present is available only for trailers; or
- a decelerometer with brake temperature readings, which can be used for vehicles without trailers or vehicles that cannot be tested on a roller brake tester, but not for trailers.
Operators must satisfy themselves that the method they use is enough to meet Regulation 18 of the Road Vehicles (Construction and Use) Regulations 1986, which requires every part of the braking system to be maintained in good and efficient working order and properly adjusted.
Traffic Commissioners treat the guide as the starting point when they decide whether maintenance arrangements are satisfactory. Where it says you should do something, that is best practice. You are not strictly required to follow it, but you should unless you can demonstrate that an alternative gives a similar level of compliance. Our article on what DVSA expects from a maintenance system explains the wider picture.
Roller brake testing
A laden test on a calibrated roller brake tester is the most effective way of measuring both individual and overall braking performance. In practice:
- Where you do not use EBPMS, DVSA expects a minimum of four laden brake tests a year, spread evenly. The annual test can count as one of them.
- A vehicle can be presented for a roller brake test up to 14 days before the safety inspection date. That lets you test it laden during normal work without loading it specially. The report must be given to the person carrying out the inspection, and a copy kept on the maintenance file.
- A signed printout should be attached to the safety inspection record. The record should show the date, how braking performance was assessed and whether the vehicle was laden.
- If braking problems appear at the annual test, at an inspection or in service, a laden roller brake test must confirm the brakes are performing satisfactorily before the vehicle is treated as roadworthy. Keep the result as evidence of the repair.
Everyone involved should understand the test report, not just file it. DVSA publishes guidance on understanding your HGV or trailer’s brake test report ↗.
When a laden test is not possible
The guide recognises some vehicles that cannot sensibly be tested laden, for example vehicles that normally run at less than 65% of their permitted axle weights for more than 70% of the time, certain dangerous goods, livestock and noxious-load vehicles, furniture removal vehicles, or vehicles whose construction prevents loading. In those cases an unladen test is acceptable, but only with a documented risk assessment completed by a competent person and evaluated at every inspection where a laden test is not done. A single risk assessment can cover a 12-month period if the use of the vehicle will not change. Keep it with the maintenance records for 15 months. Every attempt should still be made to carry out a laden test where possible.
HGVs and tractor units
The EBPMS provision applies to trailers only. For rigid goods vehicles and tractor units, the practical choices are:
- a laden roller brake test at the expected minimum of four a year, including the annual test; and
- a decelerometer with temperature readings for vehicles that cannot be roller tested. Brake temperatures should be taken before and after the test, and the final readings should be significantly higher than the starting ones and fairly consistent across each axle. A decelerometer shows overall performance but may not reveal a problem with an individual brake, so where results are not satisfactory another method must be used.
A tractor unit can pass an inspection on one method while the trailer it pulls is assessed on another. What matters is that every vehicle in your fleet has a documented brake performance assessment at every inspection, and that you can show how it was done.
What EBPMS is and how it works
An EBPMS continuously monitors the service brake performance of a trailer. A telematics unit reads braking data from the trailer’s electronic braking system (EBS), software compares the braking achieved with the braking demanded, and the result is turned into a braking performance value for the period between scheduled safety inspections. That value is compared with the statutory requirement for the type of trailer.
Because it samples every brake event in normal service, it can flag a developing problem long before the next inspection, and it can reduce the number of physical roller brake tests that a trailer fleet needs.
What DVSA requires of an EBPMS
- It must measure enough braking events over the monitoring period to produce a braking performance value. A trailer that is rarely used may not generate enough data.
- It must alert the operator to under-performing service brakes. Alerts should be recorded and investigated in the same way as defects found on a walkaround check.
- Each report must identify the trailer, the assessment date and monitoring period, and give a value for service braking performance.
- A competent person who can interpret the data must evaluate the report before every safety inspection. The evaluation must be signed and dated and attached to the vehicle record along with the performance report. The two can be a single document.
- If the system does not produce enough data, or no satisfactory EBPMS evaluation is available, use a laden roller brake test. If neither is available, a risk assessment is required, but there is still an expectation that every attempt will be made to carry out a laden test.
- After any repair or maintenance of the brakes, a meaningful laden roller brake test should be carried out before the trailer returns to service.
DVSA does not approve particular products. It points operators to its industry standard specification for EBPMS, and it remains your responsibility to make sure that the system you use meets your operational needs and the undertakings on your operator licence.
What EBPMS does not do
- It does not replace the annual test. A trailer still needs the statutory MOT brake test.
- It does not cover motor vehicles. Rigids and tractor units still need roller brake tests or, where appropriate, decelerometer assessments.
- It does not assess the parking brake. DVSA accepts a procedure for trailers with EBPMS: confirm the system is working and the data shows the brakes are within limits, have a competent person assess all parking brake components at the safety inspection, carry out a tug (shunt) test at the inspection or within the 14 days before it, with documented evidence, and check driver defect reports for any issues.
EBS, the ISO 7638 lead and Haldex
An EBPMS is only as good as the data it can see. That makes the trailer’s EBS and its connection to the tractor unit important.
It is a legal requirement for trailers fitted with EBS to be connected to the towing vehicle with an ISO 7638 ABS/EBS lead. Without it the trailer EBS will not function, and the EBPMS will not monitor the trailer’s braking performance. The lead also powers other safety systems, including anti-lock braking, faster trailer brake response, roll stability, load-sensing and air suspension. Drivers must check the lead for damage and correct connection as part of the walkaround check. If there is a fault with the lead or the trailer connection, the trailer must not be used until it is rectified. Our guide to what to expect from a FORS audit covers how the driver handbook and walkaround procedure should reflect this.
The EBS also needs to be able to share its data. Systems from makers such as Haldex, Knorr-Bremse and WABCO are the platforms that EBPMS typically reads from, and Haldex was one of the companies involved in developing DVSA’s industry standard specification. Haldex’s fourth-generation EB+ 4.0 platform is built with data connectivity in mind. In practice, a trailer’s EBS usually has to be on suitable software and configured to output data over its CAN connection before a telematics unit can feed an EBPMS, and older trailers may need updating. Before you rely on EBPMS for a particular trailer, confirm with the trailer manufacturer or your EBPMS provider that its EBS supports it and that the data is actually flowing. Look at trends rather than single readings: the performance reported reflects the trailer and the vehicle towing it, so the towing vehicle can influence the result.
Making it work in your maintenance system
- Decide, vehicle by vehicle, how brake performance will be assessed at each safety inspection: laden RBT, EBPMS (trailers) or decelerometer with temperatures (where appropriate).
- Write it into your maintenance arrangements and into any contract with your maintenance provider, and keep your planner at least six months ahead.
- Make sure roller brake tests are laden, or that there is a documented, competent risk assessment for each unladen test.
- For EBPMS, have a named competent person evaluate, sign and date the report before every inspection, and attach it to the record.
- Act on alerts. Record and investigate them like walkaround defects.
- Do not forget the parking brake. Plan the tug test and keep the evidence.
- Check the ISO 7638 lead on every walkaround. Train drivers on why it matters.
- Keep records for at least 15 months and make sure the transport manager or responsible person reviews each safety inspection record before the vehicle returns to service.
How HGV Consult can help
If you are not sure that your brake testing arrangements would stand up to scrutiny, we can help you review them. Our transport compliance support covers maintenance systems, safety inspection records and the evidence DVSA and the Traffic Commissioner expect to see, and our remote compliance audits give you an independent view of where you stand. See also our guide to preparing for a remote compliance audit.
This article is general information, not legal or technical advice. Brake testing requirements are set out in the current edition of the DVSA Guide to maintaining roadworthiness ↗, so check it, your vehicle manufacturers’ and brake system makers’ instructions and your own licence undertakings before you rely on any of it.