Work will begin on a main commuter route into Bristol next week – which will mean traffic chaos for the next six months.

Wales and West Utilities will be digging up a stretch of the A37 from Ridgeway Lane at Whitchurch, to the West Town Lane junction, to replace an ageing metal gas main with plastic pipes.

One lane of the dual carriageway will have to be closed while the work is carried out and there will be temporary traffic lights on the junction of Wells Road and Wharnecliffe Gardens.

Even longer delays than usual are expected along the A37, which is always clogged in the morning and evening rush hours anyway.

But worst hit will be businesses on the Wells Road near Hengrove Lane, and people who live along the main road who may not be able to park outside their own homes.

KwikFit tyre fitters rely on customers being able to access their Hengrove branch easily.

Sandra Payne, 62, who has run New Faces unisex hair salon for the past 29 years, was worried when she received a letter from Wales and West Utilities about the roadworks, which will continue until March 31, 2010.

She said: "I rang them because I was a bit worried about how we were going to work round it.

"Our customers park on the forecourt outside the shop and I thought we would could fit the customers in when work was not being done, but the man I spoke to said 'we will work round you'."

Customers come from all over Bristol to Ryan Turner's reptile shop, Jurassic Reps.

Mr Turner, 31, said: "Ninety-nine per cent of my customers have to drive to get here.

"I sell snakes and lizards, which is a bit of niche market.

"I did not receive a letter about replacing the gas main, but I would rather they do that than have the road explode."

A number of shops in the rank have already closed due to the recession, and traders are worried that the road works will make things worse.

Ian Harper, 54, who owns Ian Harper Models Ltd, said he had not been notified of the roadworks either.

He said: "The road was closed only 18 months ago and I lost customers then.

"My customers come from all over Bristol. I'm fuming about this. I appreciate the work has to be done but they could do it out of hours, or even at weekends."

An 86-year-old local resident, who did not wish to be named, said: "If they close a lane on our side of the road, I will not be able to park outside.

"I could leave the car outside my daughter's house but it is quite a long way for me to walk.

"We rely on the car to go out."

Wales and West Utilities replaced a stretch of gas pipes further along the A37 at Knowle four years ago, but another stretch of pipe now needs replacing.

Company spokeswoman Rachael Mullins said: "We will be delivering a gas mains replacement programme in the Whitchurch area, Wednesday, October 7. The work involves replacing a gas main from the junction with Ridgeway Lane to West Town Lane and is due to take six months to complete.

"We would like to ask people to bear with us while this essential work is carried out and apologise for any inconvenience caused."