Lives are endangered when a 40-ton truck illegally reverses down the M1 into the path of oncoming high-speed traffic, while control room staff are powerless to intervene with no patrol teams available. Elsewhere, another lorry driver hits a car and does not notice until he has driven for a quarter of a mile, while the motorway has to be closed down when a car drives into the back of an HGV.

Patrollers Mick and Mike are called to a potentially fatal incident. A man is reported running across a dual carriageway near Nottingham and a desperate call from an SOS phone soon explains why - his car has broken down on the blind corner of a slip road and his wife and children are still inside. Near Leeds, people are spotted illegally walking along the M1, so patrollers Gareth and Nick are sent to intercept them.

Patrollers Alex and Steve are called in when a horsebox catches fire, while Marissa and her team at the control centre spot a young man on CCTV threatening to jump off a bridge. Elsewhere, Keith and his engineering crew must complete a ú7 million resurfacing job over a weekend, but the works are thrown into jeopardy when a state-of-the-art machine breaks down.

At the start of a busy bank holiday weekend, patrol manager Marrissa deals with a high-speed crash outside Leeds that looks like it could be potentially fatal, while 50 miles south, Alex and Steve race to a vehicle fire.