Motorists may have to drive to Salisbury to get to the other end of the M27 this week.
The motorway will be closed in both directions between Junction 3 and Junction 5 for bridge demolition work this week.
The roadworks are set to take place between Friday, September 28 and Monday, October 1.
And the road closures will be in place from 10pm on Friday until 5am on Monday.
The closure of the motorway near Romsey next weekend is the first of three scheduled to take place over the coming 16 months.
The main diversion route will take drivers up to Salisbury and onto the A34 before coming back round to the M27 – a 58 mile diversion.
Why is the M27 being closed?
The motorway is being closed in both directions between Junction 3 and Junction 5 while Highways England replace two bridges over the carriageway.
The current bridges are said to be ‘unable to move as originally designed’ and are nearing the end of their lives – with cracks appearing in the concrete beams.
The 40-year-old bridge is nearing the end of its life and is in need of replacement.
The only safe way to do this is to close the motorway while this takes place.
The Romsey Road Bridge is well used and carries tens of thousands of vehicles daily.
The bridge is actually made up of two individual bridges, both will be closed for three full weekends while the existing bridge is demolished and a new one installed.
The replacement bridge has a different design and will have a lifespan of 120 years.
When will the M27 be closed?
The weekend closures will take place as follows:
– 10pm on Friday, September 28, to 5am Monday, October 1 – demolition of existing west bridge
- 10pm on Friday, April 26, 2019 to 5am Monday, April 29, 2019 – installation of new bridge
- 10pm on Friday, October 13, 2019, to 5am Monday, October 21, 2019 - demolition of existing east bridge.
During the work, the M27 will be closed in both directions between junctions 3 and 4, and the A3057 Romsey Road over the bridge will also be closed.
When the A3057 reopens on Monday morning, there will be a single lane over the bridge, which will be traffic light controlled.