Transport for London (TfL) has revised the Direct Vision Standard (DVS) to ease the fitting of sensors to articulated lorries.

The update is designed to prevent false positive warnings from sensors going off unnecessarily when the vehicle is turning left.

Sensors to warn a driver when a cyclist or pedestrian is coming up on the inside will be mandatory for some HGVs entering Greater London under new rules coming into force on October 26.

The DVS is designed to reduce the risk of accidents caused when vulnerable road users enter blind spots around HGVs. It is part of London Mayor Sadiq Khan’s drive to improve road safety.

One potential problem with sensors fitted to the cabs of articulated lorries is that they could be set off by the trailer when the vehicle is turning – giving a ‘false positive’ warning when no-one is in the danger zone to the nearside of the lorry.

The recent change to DVS specification spells out that sensors on artic cabs must be “suitably positioned to provide sufficient coverage, but preventing activation solely on articulation of the trailer.”

Emily Hardy, UK marketing manager of Brigade Electronics, said: “This new wording now offers more flexibility on the positioning of sensors on tractor units and resolves one of our main concerns on this specification. However operators may not be aware of the subtle change to the DVS specification.”

“We warmly welcome the changes. The previous specification stated that sensors should not be set off by street furniture – it is good to see that they now must not be set off by the lorry trailers themselves.”

All HGVs over 12 tonnes – with a few exceptions – will be rated from zero to five stars for the ease with which drivers can see people who are close to their vehicles.

Those with zero stars will not be allowed to enter Greater London without fitting a range of safety equipment including cameras, extra mirrors, side under-run protection, audible alerts when the vehicle is turning left and sensors to warn driver when a cyclist or pedestrian comes up on the inside.

Fleet operators must obtain a permit for any HGV over 12 tonnes from Transport for London demonstrating that the vehicle meets the new requirements – or face a penalty charge of £550 each time it enters the area, with a reduction for prompt payment.  The driver will also get a £130 penalty.