Road works are underway as part of a major upgrade to gas mains in a residential area of Lancaster.
Temporary traffic lights are in place on a section of the A6 Scotforth Road, one of the main roads running in and out of the city.
The work by Cadent Gas Limited began earlier this week and is scheduled to last around 10 weeks.
A letter sent to nearby properties by Cadent said: "The work is part of a big investment programme to upgrade our older gas mains.
"This will help keep you warm in your homes, with less impact on the environment."
Traffic lights are in place between close to the junctions of Addle Street and Church Avenue.
The junctions of Addle Street, Chatsworth Road and Rutland Avenue are closed.

The letter says the temporary traffic lights are expected to be in place for around six weeks, and the road closures could last two to three weeks.
Work is taking place to upgrade older gas mains, said Cadent.

The letter says further road closures are due on Church Avenue, St Paul's Road, Cheltenham Road and Hastings Road, at the junctions with Scotforth Road, in August, and a road closure is also in place on Saint Paul's Drive.
"Where road closures are in place, signed diversion routes will be provided," says the letter.
"Please also note that bus stops within the immediate vicinity of the works will be suspended for the duration of the works.
"We appreciate this may cause some inconvenience, and we thank you in advance for your patience and cooperation while these important works are carried out.
"Please be assured that every effort will be made to keep disruption to a minimum."
Businesses remain open as normal.
Lancashire County Council's online Roadworks Bulletin says Addle Street and Chatsworth Road are expected to be closed until August 8.
It says the overall work is to replace a 415m gas main, with associated services and connections, and is expected to last until September 3.


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