Traffic was brought to a stand-still yesterday as two teenagers cycled the wrong way along a busy stretch of the A12 in what could have been “a recipe for disaster”.

Police road blocks were put in place shortly after 9.30am after an initial report of a cyclist riding northbound on the southbound carriageway between Eight Ash Green (junction 26) and Marks Tey (junction 25).

A second emergency call then reported two teenagers on bicycles riding along the central reservation against the flow of traffic.

Essex Police put in rolling roadblocks on both sides of the A12 in a bid to protect the riders from coming to any harm.

Officers were unable to find the cyclists.

Adam Pipe, casualty reduction manager at Essex Police, said he could not remember another such incident.

Mr Pipe said: “This is totally unacceptable behaviour and not something we want to see. It is shocking.

“I can’t imagine what they were thinking.

“It posed not only a great risk to those riders but also to the travelling public.

“If we had caught them or managed to detect them they may have got more than a few stern words, and there is legislation which could be used to prosecute such as dangerous or careless and inconsiderate cycling.

“If something had happened a vehicle may have had to react at the last minute, and in that situation in traffic you’re hoping those around you are also reacting.

“This could have been a recipe for disaster, for a multiple casualty, multi-vehicle crash.

“There is also the disruption. Whatever we do on the A12 if we slow or halt the traffic it causes hold-ups, and if we bring the A12 to a stand-still there are hazards at the back of the queue – there’s a risk not only at the incident itself but additionally in the resulting build-up of traffic.

“Fortunately we don’t see too much of this at all, and this incident does surprise me.

“We would always encourage the public to call if they see this sort of behaviour and we will always respond.

“Of course we encourage people to use alternative means of transport and cycling is a great way of keeping fit and healthy, but riders should use cycle paths and appropriate roads, and never ride the wrong way along a road.”

The maximum penalty for dangerous cycling is a £2,500 fine, or £1,000 for the lesser offence of careless cycling.