The Forest of Dean's motorists will have 17 road closures to avoid nearby on the National Highways network this week.

And one of them is expected to cause major delays – with drivers facing a wait of at least 30 minutes. Another three 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:

• A40, from 6pm June 6 to 6am June 10, slight delays (under 10 minutes): A40 Longhope traffic lights for Gigaclear works.

• A40, from 11am June 6 to 4pm June 10, slight delays (under 10 minutes): A40 Dursley Cross, traffic lights installed by Severn Trent Water.

• A40, from 8.30am May 29 to 5.30pm June 13, slight delays (under 10 minutes): A40 / A449 both directions Travellers Rest roundabout to Welsh Border, Lane closure for horticulture (cutting and planting) works.

• M48, from 9.15am June 3 to 8pm June 28, slight delays (under 10 minutes): M48 eastbound, junction 2 to 1 Severn Bridge - lane closure for structure maintenance.

• A38, from 8pm January 8 to 6am July 31, severe delays (more than 30 minutes): M5 northbound and southbound, junction 7 to junction 11, M50 eastbound, and westbound, junction 2 to M5, carriageway, slip road, lane closures, with 24/7 narrow lanes, lane closure, and 50mph speed limit due to improvement works, diversion via National Highways and local authority network.

And a further 12 closures will begin over the next two weeks:

• A40, from 8pm June 10 to 6am June 12, slight delays (under 10 minutes): A40 Birdwood traffic lights in place for Severn Trent Water works.

• A40, from 10pm June 10 to 6am June 12, moderate delays (10-30 minutes): A40 eastbound and westbound, Huntley to Lea, junction - carriageway closure for maintenance works. Light vehicles diverted via Bradley Ct Rd and A4136. HGVs diverted via A40, A417, M50 and A449 to re-join A40.

• A40, from 7am June 12 to 5pm June 14, slight delays (under 10 minutes): A40 both directions Dursley Cross. 2-way signals for tree works on private ground.

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

• M4, from 10pm June 12 to 6am June 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.

• M4, from 9pm June 14 to 6am June 15, slight delays (under 10 minutes): M4 westbound, junction 22 to junction 23 Prince of Wales Bridge, carriageway closure for South Wales Trunk Road Agent for resurfacing works, diversion via M48 westbound.

• M4, from 9pm June 17 to 6am June 18, slight delays (under 10 minutes): M4 eastbound, junction 23 to junction 22 Prince of Wales Bridge, carriageway closure for South Wales Trunk Road Agent for resurfacing works, diversion via M48 eastbound.

• A40, from 9pm June 17 to 6am June 22, moderate delays (10-30 minutes): M50 both directions, junction 2 to Over Ross roundabout, carriageway closure for maintenance works, diversion via National Highways and local authority network.

• A40, from 8pm June 18 to 6am June 20, slight delays (under 10 minutes): A40 Huntley traffic lights in place for Severn Trent Water works.

• M5, from 9.30am June 19 to 3.30pm June 20, slight delays (under 10 minutes): M5 northbound, junction 12 exit slip lane closure for Gloucestershire County Council grass cutting works.

• M5, from 9pm June 20 to 6am June 21, slight delays (under 10 minutes): M5 southbound, Michael Wood Services closed (no access to services) for carriageway repairs.

• A449, from 9pm June 24 to 6am June 25, moderate delays (10-30 minutes): M50 westbound, junction 2 to junction 4, entry and exit slip road and lane closure for maintenance works, diversion via National Highways and local authority network.

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