Annual truck test first-time pass rates hit all-time high

The roadworthiness of UK trucks, as measured by their performance at their annual test, has hit a record new high, with three-quarters of all trucks passing at the first attempt.

According to Vosa’s Annual Effectiveness Report published this month, the initial pass rate for trucks tested in the 12 months to 31 March 2012 rose to 75.3%.

This is one percentage point above the previous year’s figure, and the fifth successive increase.

The pass rate for trailers also reached an all-time high in 2011/12, rising for the 10th year in succession to reach 82.7%, up from 82.1% in 2010/11.

A steady improvement

This steady improvement in test performance echoes the increase in the proportion of tests conducted at non-Vosa test sites, such as authorised testing facilities (ATFs) and designated premises (DPs). A total of 32.6% of truck tests and 45% of trailer tests took place at non-Vosa sites in 2011/12, up from 24.6% and 35.2% respectively a year earlier.

Before the introduction of ATFs, Vosa chief executive Alastair Peoples had predicted that transferring testing to privately run premises would improve test performance, as maintaining and testing vehicles on the same premises with the same brake-test rollers and headlamp aim equipment is bound to pay dividends, as would eliminating the journey from workshop to test site.

Vosa’s figures highlight these benefits, with pass rates at non-Vosa sites better than at Vosa’s own test stations (76.6% versus 74.6% for trucks, and 84.2% versus 81.5% for trailers).

There is little change in the top reasons for test failures. Headlamp aim remains the biggest single defect, listed as a failure reason in 10.9% of all truck tests. But thanks to the introduction of less-stringent aim requirements four years ago, this is half the proportion of tests that used to result in failure due to wayward headlamp beams.

Other lamp faults came second (4.8%), followed by service brake performance (4.1%) and brake system components (3.8%).

Main reasons for trailer failures

In the case of trailers, braking defects account for three of the top four reasons for failures. Service brake performance is top of the list, mentioned as a failure item on 8.7% of all tests. This is followed by parking braking performance (5.7%); lamps (3%) and brake system components (3%). But the proportion of trailers failing for these four reasons is following a downward trend over recent years, helping to boost the overall first-time test pass rate.

Vosa’s current testing year comes to an end on 31 March and, as the number of ATF sites continues to increase, it seems probable that the next results will be even better than these 2011/12 figures. Vosa data for LGV tests conducted in the first two quarters of 2012/13

(1 April to 30 September 2012) reveal that the first-time test pass rate is now close to 77%, while trailers are running at more than 84%.

Pass rates for 3- to 3.5-tonne vans

The most concerning result in the report is the test performance of 3- to 3.5-tonne vans in MoT class 7. Their first-time pass rate in 2011/2012 was 50.2%, showing no improvement. This is worse than the car and light van test performance (59.9% pass rate) and is particularly significant when combined with the steady growth of heavy vans on UK roads.

Despite these improvement in truck test performance, the industry still has some way to go before it can match the bus and coach sector. The first-time test pass rate for buses and coaches in 2011/2012 was 81%.

Nevertheless, the gap between the sectors is closing: 10 years ago the bus and coach pass rate was 12 percentage points better: now the margin is down to less than half that.

  • Vosa recently opened its 300th ATF in Plymouth (although this figure includes private sites used exclusively by operators and not open to the general road transport market).