Safety radar technology meant to detect stranded cars on smart motorways is missing up to 40 per cent of stopped vehicles and “falling short” of minimum targets.
A watchdog report found alerts that should happen within 20 seconds took more than a minute in one region, and that more than four in five alerts were false alarms in another.
The Office of Rail and Road (ORR) said while National Highways had met deadlines to install safety technology, “urgent action is needed” to address its performance.
Stopped vehicle detection (SVD) is a type of radar system that flanks controversial all-lane running motorways (ALR) where the hard shoulder has been converted to a live lane.
It means broken down vehicles are left marooned in high-speed traffic until control room staff find the incident on camera, set lane closures and dispatch traffic officers to the scene.
SVD should alert control operators to stationary vehicles within 20 seconds. National Highways staff members can then check CCTV cameras and confirm the situation before setting the appropriate signs and signals.
National Highways’ minimum requirements for SVD is that it detects 80 per cent of stopped vehicles and sends a maximum 15 per cent of false alarms.
But a watchdog report found the technology fell behind these targets in each of the five regions.
Lives ‘being put at risk’
The report, published on Thursday, said: “Overall performance is not yet at the level the company set itself and urgent action is needed.”
In the Midlands, the worst performing area, only 59.6 per cent of stationary vehicles were detected, while 83.5 per cent of alerts were false alarms.
Meanwhile, only one region met the 20-second alert target. Other than the North West, every area took between 43 and 65 seconds to send an alert to control room staff.
MPs and campaigners have called on the Government to immediately reinstate the hard shoulder over fears lives are “being put at risk”.