Engineering work has started on a major £13m project to improve tap water.
United Utilities engineers are cleaning and upgrading a waterpipe from Westby into Blackpool.
The latest work at the Devonshire Road and Warbreck Hill roundabout will take up to eight weeks to complete. Devonshire Road is closed to traffic travelling southbound, with a diversion signposted.
Temporary traffic lights are in place to let traffic travel north along Devonshire Road and east or west bound along Warbreck Hill Road.
The water pipe improvement scheme, which began in February and continues until summer 2017, will improve water quality for around 50,000 properties in Blackpool, Lytham and St Annes.
A total of 17km of water pipe will be cleaned and refurbished in total.
A United Utilities spokesman said: “Our apologies to motorists for any delays while we complete this essential work.
“This scheme is all about delivering even better tap water for the area, by upgrading sections of pipe, and giving others a thorough clean to remove natural mineral deposits. Given the scale of project, we sometimes have to work in inconvenient locations, such as this one. We will, however, do everything possible to keep traffic flowing.”