The systems also raise the alarm when there is a medical emergency.

The contractor has now chosen the Skyguard lone worker device which is being rolled-out to 450 staff in its highways division.

The system links staff to a call centre and they can use two alarm functions.

The ‘SOS’ button connects to the Skyguard internal call centre within 30 seconds and the other is a ‘man down’ function which raises an automatic alarm if the device suffers a sudden impact.

During the trials a device had to be used for medical assistance, alerting the emergency services who attended the injured party within seven minutes of activating the device.

Another incident occurred when a Ringway winter maintenance spreader hit a patch of black ice causing it to leave the carriageway, falling onto its side.

Although the driver wasn’t seriously injured he was wearing his Skyguard device and pressed the SOS button.

He was able to speak to the call centre team while waiting for the ambulance which was on site ten minutes after the incident occurred.

Ringway have bought a total of 450 devices so far and have rolled them out across the Highway infrastructure service business.

Ringway Jacobs are also planning to roll these out for similar lone worker tasks.