At last – work is to start this week on solving the flooding problems at three locations on Dorchester bypass.

Engineers will also install motion sensitive Toucan lights at the Stadium Roundabout to improve safety while crossing five lanes of traffic for cyclists and pedestrian.

Other works planned in the area by Highways England and Dorset Council include completing the gaps around Dorchester on the national cycle route which runs from Portishead to Portland and stopping verge parking outside McDonalds.

The news was given to a Dorchester Town Council meeting on Monday evening by councillor Roland Tarr, who represents parishes south of the county town on Dorset Council.

He said Highways England staff appeared shocked when they discovered how bad the flooding problem has been – with long term flooding at the Monkey's Jump roundabout; half way between the Stadium roundabout and the Max Gate turn off and on the slip lane at the same junction when approaching from the east.

In the past the Stadium roundabout has also flooded although interim work three years ago clearing soakaways seems to have largely solved that.

Dorchester Town Council has been campaigning for several years to solve the flooding which, at times, has resulted in the complete closure of the bypass forcing all through traffic into the town.

Work had been programmed to start in the next financial year but has now been brought forward after a successful bid for government funding.

Several town councillors welcomed the news.

Cllr Richard Biggs said having lights on the Stadium Roundabout would remove a major obstacle for many people cycling and walking between Dorchester and Weymouth. He said a lot of bike riders feared crossing the road at the busy roundabout so much that they would cycle the extra distance around Herringston Road to avoid it.

Others, including David Leaper, said the lights were only likely to result in minor delays for drivers: "I do cycle to Weymouth or Portland occasionally and it's a nightmare at the roundabout…this is a splendid idea," he said, although that route with blind bends and hills was not much safer.

Mayor Cllr Gareth Jones said he also used to cycle the route to get to and from work: "You were always taking your life in your hands," he said.

Cllr Frances Hogwood, who is working on safer cycle and walking routes in the town, said all the cyclist groups she had contacted focused on the danger of the roundabout crossing as a major barrier to more people cycling.

Cllr Tarr said that work was likely to mostly take place between midnight and 6am with road closures in place 8pm until 8am. The work is likely to start at the Monkey's Jump roundabout, working around the bypass towards the Max Gate junction.

Mr Tarr, a cycle campaigner, said he also welcomed the pledge to improve the Route 26 cycleway which had problem areas around Frome Vauchurch and Frampton.

"If it can be completed it will attract people in…some do sleep in tents, but many don't bat an eyelid at spending £200 a night which would help keep our rural pubs and B&Bs going," he said.