In June thousands of motorists were stuck in an eight-hour traffic jam on the M25 caused by an intense petrol tanker fire.
The jam stretched for 29km but stranded motorists could not be diverted off the road because that section of the London Orbital has no emergency cross-over points in the central reservation.
Highways Agency officials hastily announced a review of emergency access to the motorway network as a result, but at Great Barford they are one step ahead.
Nuttall has installed two emergency access gates on the 7.7km route on the advice of the Agency's Managing Agent and Contractor Carillion URS.
The gates are 17m long steel box beams that have hidden wheels requiring only a ratchet spanner to lower them into position beneath the steel barrier. Once lowered, they can be pushed by hand into the open position to divert traffic onto the opposite carriageway. This can be done, according to manufacturer Asset International, by a single operator in five minutes.
There are also plans for one gate to be installed on the Caxton improvement scheme.