CHRISTMAS is coming but there clearly no way work on Cunningham's Gap will be completed in time for the silly season, with projects now having blown out until close to the middle of next year.

As weary motorists and freight operators continue the long, slow haul up and down our only Range crossing - and the wet season approaches - Main Roads yesterday conceded that one of the most difficult repair points, at Clayton's Gully, is worse than at first thought.

The heavy rains of last summer caused what the department describes as "some of the worst damage ever inflicted on the Gap", through rock falls, erosion and below-the-road subsidence.

A Main Roads spokeswoman yesterday said while no new sites had been added to the 11 already being worked on, new tenders had been called for Clayton's' Gully, a major channel running under the highway near the truck emergency stopping bed.

"We have been working hard to finalise the design for Clayton's Gully - the 11th and final site at the Gap - and we've also completed reconstruction at four sites, with another six to be finished by the end of the year," the spokeswoman said.

"Geotechnical monitoring at Clayton's Gully has revealed the embankment is unstable to a depth of 12 metres.

"That's why the new design involves a new stretch of road 600 metres long and four lanes wide cutting a massive 50 metres into the embankment to provide a stronger surface.

"Prospective contractors are currently tendering for the work, with construction due to start early 2012."

The spokeswoman gave no timeframe on when the Clayton's Gully work might be complete, or indeed any of the other work continuing into 2012, but new signage in place on the highway offers a vague "mid-2012".

"There are no delays or additional costs with the work at Clayton's Gully in 2012 and no new sites have been identified for reconstruction," the spokeswoman said.

"About 130,000 square metres of rock will be removed using a 40-tonne excavator and possibly specialist rock breaker equipment in the (Clayton's Gully) project.

"Clayton's Gully was the worst hit section of Cunningham's Gap after a massive landslip left a potential sinkhole of 50 by 80 metres - the size of three Olympic swimming pools."