Drivers in and around the Forest of Dean will have 15 National Highways road closures to watch out for this week.

And one of them is expected to cause severe delays – with motorists facing a holdup of at least 30 minutes. Another five will cause moderate delays of between 10 minutes and half an hour.

The latest expected works list, with notes from National Highways, shows that five closures already in place are expected to carry on this week:

• M48, from 9pm April 3 to 6am July 5, slight delays (under 10 minutes): M48 both directions mobile lane closure for drainage works.

• A40, from 8pm June 26 to 6am July 14, moderate delays (10-30 minutes): M50 both directions jct two entry and exit slip roads, lane closures with closure of slip roads for resurfacing works on part A417 by Gloucestershire County Council.

• M4, from 8pm May 30 to 6am July 18, moderate delays (10-30 minutes): M4 both directions, junction 22 closed between exit and entry slip road for carriageway repairs. Diversion via exit and entry slip roads.

• M48, from 9pm April 27 to 6am July 29, slight delays (under 10 minutes): M48 both directions mobile lane closure for drainage works.

• M50, from 6.44pm March 7 2023 to midnight, January 1 2026, slight delays (under 10 minutes): M50 both directions jct one to jct two, no full closure in this location without approving the diversion.

And a further 10 closures will begin over the next two weeks:

• M48, from 7pm July 3 to 6am July 5, moderate delays (10-30 minutes): M48 eastbound, junction 2 to 1 Severn Bridge - carriageway closure for structure maintenance. Diversion via M4 Prince of Wales Bridge.

• M48, from 7pm July 3 to 6am July 5, slight delays (under 10 minutes): M48 westbound, Severn Bridge, junction 1 to 2 lane closure for maintenance works.

• M5, from 8pm July 4 to 6am July 5, slight delays (under 10 minutes): M5 northbound, junction 13 to 12 hard shoulder closure for barrier repairs.

• M48, from 7pm July 5 to 6am July 7, moderate delays (10-30 minutes): M48 westbound, junction 1 to 2 Severn Bridge carriageway closed for structure maintenance works. Diversion via M4 Prince of Wales Bridge.

• M48, from 9pm July 5 to 6am July 7, slight delays (under 10 minutes): M48 eastbound, junction 2 to 1 Severn Bridge - lane closure for structure maintenance.

• M4, from 9pm July 10 to 6am July 12, moderate delays (10-30 minutes): M4 eastbound, junction 23 to 22 Prince of Wales Bridge - carriageway closure for bridge maintenance, diversion via M48 Severn bridge.

• M4, from 9pm July 12 to 6am July 14, slight delays (under 10 minutes): M4 eastbound, junction 23 to 22 Prince of Wales Bridge - lane closure for structure maintenance.

• M4, from 10pm July 12 to 6am July 14, slight delays (under 10 minutes): M4 westbound, junction 22 to 23 Prince of Wales Bridge - carriageway closure for structure maintenance, diversion via M48 Severn Bridge.

• A40, from 8pm July 17 to 6am July 26, severe delays (more than 30 minutes): A40 both directions between Dursley Cross and Huntley (B4216) carriageway closures for resurfacing, Light vehicle diversion via B4224, A4136, A4151 and A48, HGV diversion via A40, A449, M50 and A417.

• M4, from 8pm July 17 to 6am July 18, slight delays (under 10 minutes): M48 westbound, M4, junction 21 to junction 1 carriageway closure for maintenance, diversion via M4, junction 23a Magor and return.

National Highways is responsible for maintaining motorways and major A-roads, so closures of smaller roads will not be included in their schedule.