National Highways clarifies SVD retrofit pledge

National Highways has insisted that it will have stopped vehicle detection (SVD) up and running across its smart motorway network by its September target, despite recently suggesting that it would count schemes where the technology is still being calibrated.

Last week, the government-owned company published its second annual update on progress against the Government’s 2020 Stocktake and Action plan, which stated that it had put SVD in place on over 100 miles of All Lane Running (ALR) motorway.

It said the company was 'still on track to complete the roll out of SVD on more than 200 miles (in total) of ALR motorway by the end of September 2022’.

It added a footnote, suggesting that it counts SVD as installed ‘following initial calibration where SVD alerts begin activating and are responded to within our regional control rooms [but] we continue to calibrate the SVD system’.

National Highways has clarified that for the purpose of its target, it will only consider SVD to have been installed on a scheme when calibration has been completed to the point where the national speed limit has been reinstated and operators are able to act on alerts by, for example, closing lanes.

However, this process can take a long time. On National Highways’ latest ALR scheme, on the M27 in Hampshire, which had other traffic management removed in February as a necessary part of fine-tuning the equipment, a 60mph speed limit remains in force, in line with a pledge that no new ALR scheme will open without SVD.

This appears to reflect a high level of caution following recent crashes of the M4 and M3 where alerts were not raised in response to stationary vehicles in live lanes. Even after the process has been completed, continuous improvement of the technology will continue.

National Highways has said it has brought forward the target for retrofitting SVD to existing ALR schemes – originally March next year – by six months.

However, the Government-owned company says the roll-out target now only covers operational schemes, whereas the original programme in its 2020-25 Delivery Plan included schemes, such as the M27, that were due to be opened before the deadline.

While the changed definition for the retrofit target means National Highways can claim to have met the accelerated deadline of September, by delaying the full, speed limit opening of some smart motorway schemes, it will also be performing no better than its original plan.

Although National Highways has said that the M27 scheme will be fully open by the September deadline and another new scheme covering the second of two new ALR sections of the M4 is likely to fully open soon, four schemes from the original programme are at risk of being completed after September.

ALR schemes on the M1 junctions 13-16 and M6 junctions 21a-26 are now due to be completed after September In addition, two schemes that are currently due to open in the summer could potentially open after September.

The opening date for the ALR scheme between junctions 6 and 8 of the M56 has already been put back to this spring for SVD to be installed. However, the scheme has been further delayed and the removal of physical traffic management to allow calibration of SVD may not begin until October.

Like the M56 scheme, the end date for a scheme to convert a section of the M6 between junctions 13 and 15 to ALR was also put back to the spring for SVD to be installed. National Highways has now completed substantive works and last week removed traffic management on the Northbound carriageway, with the 60mph limit still in force, while SVD is calibrated. This was already happening on the Southbound carriageway.

However, given that the calibration of SVD on the M27 is now into its fourth month, it is by no means certain that the same process will be completed on the M6 scheme by September.

With the original programme listing eight schemes to be completed during the current financial year, for four schemes to be completed after September would mean that progress has been no quicker under the ‘accelerated’ programme than the original one.

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