Bath and Bristol face roadworks disruption
Gas mains work in Bath and Bristol is expected to cause disruption for several months in both cities.
Work on London Road, in Bath, from the junction of Margaret's Hill and Snow Hill, is expected to last 10 weeks.
In the Temple Meads area of Bristol, work to replace 1km (0.6 miles) of old pipes and is expected to take 18 weeks.
Wales and West Utilities (WWU) said the work was essential to maintaining gas supplies, but some traders said they wished they had been told earlier.
The project in Bath will replace more than 360m (394 yards) of old metal gas pipes with new plastic pipes.
Alex Schlesinger, an antiques dealer who is chairman of the Snow Hill Partnership, said he depended on passing trade and that August was one of the busiest months for holiday traffic in the city.
He said: "They've given us very little notice. It's not just the traders, it's residents as well.
"I think we should have had a letter in good time."
The work in Bristol is taking place from the Temple Circus Gyratory to the junction of Feeder Road, via Victoria Street, Temple Gate and Cattle Market Road.
Ben Moss, from Bristol Wood Recycling Project, said: "It came to us as a surprise, we just saw the signs at the end of the road.
"I'm very concerned about the affect it will have on our business. We're not going to have as much passing trade. Even regular customers are going to find it hard to access."
Colin Langdon, WWU's operations controller, said they were using keyhole techniques to insert the new pipe into the existing one, to minimise disruption and excavation.
He said: "We hope that, with the co-operation of local residents and businesses, this important gas replacement work will be completed on schedule and with minimal disruption.
"The new non-corroding plastic pipes will have a lifespan of more than 80 years."