The traffic system on part of the England's smart motorway network - already controversial because of motorist deaths and safety concerns - was unexpectedly out of action for two hours this morning.
It happened from "around 8.30am and lasted until around 10.30am", says National Highways, which runs the network.
CCTV was still operational during this time, it says, and the south-east and east of the country was not affected.
The organisation insists: "There were no major incidents or serious congestion reported on the network during this period."
The UK government announced last year that development of these all-lane running highways will be put on hold for another few years to assess safety data.
But in the meantime, the existing smart motorway network operates with hard shoulders used as lanes for vehicles - meaning safe spaces for breakdowns is limited to specific refuge areas.
“We are urgently investigating an unplanned outage of our traffic management system that took place this morning," said operational control director Andrew Page-Dove.
“Engineers worked hard to get the system back online as soon as possible and we apologise for any inconvenience caused."
“We have well-rehearsed procedures to deal with issues which arise," continues Page-Dove. "We rapidly took steps to help ensure the safety of road users such as increased patrols and CCTV monitoring.”
