VISITORS heading to Bournemouth on one of the warmest days of the year so far are likely to face traffic chaos as a result of extensive motorway closures.

Drivers will be diverted off the M27 this weekend when the motorway closes between junctions 3 and 4 for Highways England's work on Romsey Road Bridge. Temperatures are expected to reach 25C on Friday and 23C on Saturday before cooling to 19C on Sunday.

Traffic chiefs are warning drivers to expect “significant delays”.

The warning comes as Highways England announced the diversion routes for this weekend’s closure, which begins at 10pm on Friday.

Westbound traffic will be via M3 junction 11 down the A3090 through Romsey and down the A36 to M27 junction 2.

Lorries will be diverted off at M27 junction 5, along the A27 to Chilworth roundabout, then along the A27 through North Baddesley, down the A3057, onto the M271 and re-joining the M27 at junction 3.

Eastbound, light vehicles on the M27 travelling from the A31 to London/M3 will be diverted off at M27 junction 2 to use the A36 and the A3090 through Romsey towards M3 junction 11.

HGVs on the M27 coming from the A31 heading for London will be diverted off the above route at Romsey, onto the A27 and the A33 to join the M3 northbound.

Traffic of any type on the M27 coming from the A31 and heading towards M27 east will be diverted at junction 3 to head up the M271 and A3057 northbound.

Traffic will then be diverted, before it reaches Romsey, to join the eastbound A27, heading through North Baddesley to re-join the M27 at junction 5.

The closure, which is expected to last until 5am on Monday, July 1, is to allow engineers to install the new Romsey Road Bridge.

It follows a closure in September to allow the demolition of part of the old bridge.

The new bridge weighs 1,069 tonnes – as much as 15 space shuttles - and will be lifted into place using self-propelled modular transporters, which are remote-controlled, self-powered low-loader lorries.

Highways England project manager Andrew Winson said: “The installation of the new Romsey Road bridge marks a major milestone in this scheme and is the next step towards opening a brand-new bridge for people in the area and users of the A3057.

“Our approach to replacing this bridge has meant that we can avoid months of disruption on the M27 and carry out the big operations over three weekends, spread out over time.

“But, while this means less disruption overall, closing the M27 will inevitably cause disruption, so I strongly urge drivers to plan ahead and avoid the area if possible.

“The weather is expected to be very warm this weekend, so if travelling by car, please take some extra water on your journey just in case the diversion routes are busy, which they are expected to be.”