Transport for London (TfL) is having to rethink its proposed direct vision standard (DVS) for trucks, after the aborted publication of initial star ratings for the scheme revealed that most of the large commercial vehicles on the road today would not meet requirements – as Paul Strang, senior strategy and planning manager (freight and fleet) at TfL, told the Freight Transport Association’s recent Fleet Engineer Conference in Coventry.
The DVS system – which features a zero-to-five star rating model to decide which trucks should be allowed to operate on London roads – was designed to reflect the level of direct vision available to drivers from the cab of each HGV model, in a bid to improve safety for other road users in the capital.
But industry stakeholders had previously raised concerns about the potential high costs to transport operators who had recently faced significant outlay to purchase emissions-compliant Euro 6 trucks for operation in London, only now to see them restricted or banned due to the new direct vision rules.
“The direct vision standards are very important to the London mayor, and to me,” said Paul Strang (right), adding that the large conurbations of London and Manchester had much higher cycle versus truck accident rates than other parts of the country.
Direct vision was thought to be important because drivers tended to respond slower to indirect stimuli, such as a cyclist seen in a mirror or on a CCTV screen, than to a cyclist seen directly through a window, he said.
“But direct vision is not a panacea. Other safety aspects need to be taken into account, too,” he said.
This acknowledgement tallies with the tone struck in the preamble to the latest consultation on the scheme, launched in November, which closed in late January.
In this, TfL had promised a ‘more holistic approach’ to truck safety rather than concentrating on direct vision alone. The authority also conceded that truck manufacturers were some way off producing sufficient redesigned cabs to cater for London operators – and recommended the adoption of a safety permit scheme, rather than an outright ban on certain truck models.
As a result, while direct vision would remain at the heart of the proposals, TfL said it also planned to take other aspects into account via its permit scheme, namely: indirect vision aids designed to minimise blind spots; warning systems to alert other road users to intended manoeuvres; physical ‘hardware’ on HGVs’ exteriors designed to reduce the risk or impact of a hazard; and urban driver training focusing on vulnerable road user safety.
The direct vision star rating would determine the level of input required from these other elements. For example, from 2020 when the first phase of the scheme is planned to come into force, an HGV rated zero for direct vision would not be granted a permit unless other elements were addressed.
Blind spots were the biggest factor in urban cycle versus truck accidents, but there were other causes, Mr Strang admitted.
“A cyclist colliding with a truck’s rear axle won’t be saved by a driver sitting in a greenhouse cab.”
Much of the legwork in drawing up the DVS had been done by Loughborough University; and Dr Steve Summerskill (right), a senior lecturer at the university’s design school, explained what had been done and why.
Direct vision was important, because “it takes a driver at least five seconds to scan six mirrors and three windows,” he said.
In 2010, the University had modelled cabs from Scania, Volvo and Renault trucks to see what a driver could see in the mirrors. A blind-spot between what could be seen in the then-current ‘look-down’ mirror and what could be seen in the window had led to the new mirror standard that had been subsequently introduced.
The next exercise had sampled 99 per cent of current truck cab designs. Unsurprisingly, it had found that the higher a particular cab was mounted, the greater the angle of obstruction was. But there were also significant differences between seemingly similar cab designs.
For example, with cabs mounted at identical heights, there was over a metre wider blind spot on an MAN cab than there was on a Scania, because the Scania had a deeper door window.
Of 23 out of 33 vehicle designs tested, it was only possible to see the heads and shoulders of someone if they were 4.3 metres or more away from the vehicle.
One problem with assessing the different cab designs was finding the driver’s eye point, so this was one of the parameters which was being redefined for the DVS.
There was a separate programme looking at driver vision on buses, which would use lessons learned from the truck exercise.
The politicians driving the initiatives were promoting: “Vision Zero: the principle that no road death is acceptable. There is no single solution that will achieve this, and everything is in the mix,” he said.
Speaking at the Iveco State of the Nation press conference in mid-January, Iveco’s director of alternative fuels, Martin Flach, pointed out that truck cab designs had lives of 30 years, and that many of Iveco’s competitors had recently introduced all-new designs which took no account of TfL’s scheme.
“The direct vision standards are all about London,” he said.
“Like the other truck manufacturers, Iveco applauds TfL’s objectives, but the system as proposed just illustrates that local politicians are hopeless at making legislation. The star ratings as published on the TfL website were misleading. They were wrong.
“No manufacturer is going to design a cab just for London.”
In related news, Scania is to introduce a factory-installed kerb vision window as a £600 option on new trucks. The Scania City Safe Window is heated and will be available on New Generation P-Series and the recently-launched low-entry L-Series cabs.