Drivers in and around the Forest of Dean will have 17 National Highways road closures to watch out for this week.

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

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

• 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.

• 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 14 closures will begin over the next two weeks:

• 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.

• A40, from 7pm June 3 to 5am June 6, slight delays (under 10 minutes): A40 Huntley to Highnam traffic lights in place for Gigaclear works.

• M4, from 8pm June 3 to 6am June 5, moderate delays (10-30 minutes): M48 eastbound, junction 2 to junction 1 Severn Bridge carriageway closure for structure maintenance, diversion via M4 Prince of Wales Bridge.

• A40, from 8pm June 3 to 11.59pm June 5, slight delays (under 10 minutes): A40 Longhope traffic lights in place for Severn Trent Water works.

• M48, from 8pm June 3 to 6am June 5, slight delays (under 10 minutes): M48 westbound, junction 1 to 2 Severn Bridge lane closure for structure maintenance works.

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

• A40, from 10pm June 6 to 6am June 7, slight delays (under 10 minutes): A40 eastbound, Highnam Rbt to Over Rbt, lane closure for drainage works.

• 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 10pm June 14 to 8pm June 16, moderate delays (10-30 minutes): M48 eastbound, junction 2 to junction 1 Severn Bridge carriageway closure for structure maintenance, diversion via M4 Prince of Wales Bridge, diversion for, junction 1 via M4, junction 19, M32, junction 1 and return.

• 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.

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