Drivers who face months of misery on the A27 despite a £1m building project being ahead of schedule have been advised to take the train.

The Highways Agency is creating a subway at Falmer for university students and employees. It is due for completion next month and looks set to finish early, although officials refuse to say when.

A spokeswoman said: "We set down an allotted time and it seems the work has gone well. There have been no hitches but we do allow for a longer period in case there are problems."

An eastbound lane that was closed for three days because of flooding caused by a spring was opened on Monday.

But despite this respite for drivers, more work is being planned for the busy dual carriageway. Norman Baker, MP for Lewes, said people should consider using trains between Lewes and Brighton to avoid the congestion.

He said: "The solution must be to minimise the amount of time the road is out of normal behaviour and to ensure as much work as possible is done outside rush hour."

A project to build a slip road at the Little Chef on the westbound carriageway between Falmer and Lewes will start in May and last for about three weeks.

In October, drainage work on the eastbound road in the same area will close one lane for up to three weeks.

A Highways Agency spokeswoman said: "It is all in the motorists' interest. We need to put in deep drains to reduce the floods."

The Falmer to Lewes stretch has been a cone zone for motorists since May last year when the agency started drainage works.

After those stopped in September, work began to build the subway for Sussex University students.

Councillor Andrew Small, Cabinet member for planning and transport at Lewes District Council, is angry about the amount of work being carried out on that particular stretch.

He said: "I am disgusted with the way the Highways Agency has carried out its work on the A27. Over the past two to three years they have had extensive roadworks on the drains causing disruption to road users and it has proved to be absolutely useless."

The agency will be holding an exhibition for outstanding works on the A27 in Lewes this month.

It will include plans for a flyover across the railway at Beddingham and new roundabouts at Southerham and the junction with the A26.

The agency says the flyover is needed to prevent accidents at the Beddingham level crossing, disputed by anti-road campaigners who claim accident figures have been inflated.

The agency will be holding its exhibition at Lewes Town Hall from 5pm to 9pm on January 17 and from 10am to 3pm on January 18