Headlamp aim remains top reason for heavy vehicle test fails
Headlamp aim remained the top reason for trucks failing their annual tests in 2011-12, according to the latest report from VOSA, with nearly 11 per cent of HGVs presented for test failing for this cause.
Of all commercial types, HGV trailers were the best-prepared for test, with an initial fail rate of 17.3 per cent. Nineteen per cent of buses and coaches failed their first tests, while for trucks the initial fail rate was 24.7 per cent. All these classes show a continuing slight improvement over previous years in spite of an ageing national parc of trucks, trailers and buses.
The most common reason for trailers failing their tests was service brake performance (they were twice as likely to be failed for this reason as trucks were), while for buses and coaches it was, like trucks, headlamp aim (seven per cent). Those preparing vehicles for test admit that this is one of the most notoriously difficult areas to get right: what seems to be correct when it leaves the workshop can appear to be wrong when it is examined by VOSA.
Roadworthiness of commercial vehicles with gross weights between 3,000 and 3,500 kg remains a serious issue, with 49.8 per cent failing their initial test, a figure which is slightly worse than last year’s. In contrast, the failure rate for the combined passenger car and light goods category was 40 per cent.
The heavy van statistics are so concerning as to be worthy of further examination: 21 per cent of vans tested had defective brakes; on 11.3 per cent the driver’s view of the road was obstructed; and a staggering 28.8 per cent were presented for test with defective lights and/or indicators. Fifteen per cent had defective suspension. There was an average of over three faults per vehicle on those that failed (which, it must be remembered is just under a half of all those presented for test). Clearly, the heavy van sector contains a considerable number of operators for whom roadworthiness is an issue which is only addressed once a year: after the van has failed its test and has to be put right again.
First-time failure rates for trucks, trailers and PCVs remain pretty much unchanged over the last three years, with a slight improvement each year.
Interestingly a higher percentage of each class of vehicle records a first-time test when tested at a non-VOSA operated-facility than they do when presented at a VOSA test station. As VOSA personnel perform the actual test at both types of premises, the most likely conclusion is that the vehicles tested at the private premises are better prepared for the test.
In terms of trends, warning lamps has become a top ten item for trucks, replacing bumpers and sideguards, and speedo/tacho replaced steering mechanism in the top ten for PCVs.
