THE M48 Severn Bridge crossing will close overnight for three nights this week, here is why.

National Highways will be closing the M48 Severn Bridge this evening, from 8pm on Tuesday, May 7 until 6am on Wednesday, May 8.

The highways operator has said this is because of "scheduled structure maintenance", which will close the M48 eastbound junction 2 to junction 1 Severn Bridge carriageway.

South Wales Argus: The bridge crossing will be closed for overnight for three nights this week.The bridge crossing will be closed for overnight for three nights this week. (Image: File)

This will also be the case from 8pm on Wednesday, May 8, until 6am on Thursday, May 9, where diversions will be in place via the M4 Prince of Wales Bridge and via M4 junction 19 or M32 junction 1 and return.

From 8pm on Thursday, May 9 until 6am Friday, May 10, the M48 westbound junction 1 to junction 2, Severn Bridge carriageway will be closed for the structure maintenance works. A diversion via M4 Prince of Wales Bridge will be in place from Thursday to Friday.

Bridge maintenance

National Highways has made it clear that "the bridges need frequent maintenance to keep them in a safe and serviceable condition."

The road surface on the M48 Severn Bridge is narrower than a typical motorway, so there is less space for engineers to carry out maintenance. This means that the Severn Bridge needs to be closed more often than other motorways.