Guide
Carry out works affecting the strategic road network
How to obtain National Highways approval before carrying out works on or adjacent to motorways and trunk roads in England. Covers DMRB design standards, the design review process, road space booking, technical approval for structures, traffic management requirements, and penalties for unauthorised works.
If you need to carry out works on or adjacent to a motorway or trunk road in England, you must obtain approval from National Highways before any work begins. National Highways is the highway authority for the Strategic Road Network (SRN), which comprises approximately 4,500 miles of motorways and trunk roads. This requirement applies to all types of works, including temporary traffic management, connections and junctions, structures, drainage, lighting, and signage.
The approval requirement comes from Section 175 of the Highways Act 1980, which restricts works affecting trunk roads and special roads. Carrying out works without approval is a criminal offence, and National Highways can require you to remove unauthorised works at your own expense.
This guide applies to contractors, developers, and utility companies carrying out works on the SRN in England. It does not cover local roads managed by local highway authorities, trunk roads in Scotland (managed by Transport Scotland), trunk roads in Wales (managed by the Welsh Government), or trunk roads in Northern Ireland (managed by the Department for Infrastructure).
Design Manual for Roads and Bridges (DMRB) standards
All works on or affecting the Strategic Road Network must comply with the Design Manual for Roads and Bridges (DMRB). This is the technical standard published under the authority of National Highways that governs the design, construction, and maintenance of the SRN.
The DMRB covers a wide range of technical requirements including:
- Geometric design - road alignment, junction layout, and visibility requirements for the speed and traffic volumes on the SRN
- Structural design - bridges, retaining walls, gantries, and other highway structures must be designed and checked in accordance with DMRB technical approval procedures
- Drainage design - surface water drainage, attenuation, and pollution control for highway runoff
- Pavement design - road surface and foundation layer specifications for the traffic loading on the SRN
- Environmental assessment - noise, air quality, landscape, and ecology impacts of works on the SRN
In addition to the DMRB, the Manual of Contract Documents for Highway Works (MCHW) sets out the construction specifications for materials, workmanship, and testing. Compliance with both DMRB and MCHW is mandatory for all works on the SRN.
If you are working on a local road but your works affect the SRN (for example, a development that requires a new junction onto a trunk road), you must obtain National Highways approval for the elements that affect the SRN, even though the local highway authority manages the local road.
Apply for approval step by step
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1. Identify the National Highways regional team
The SRN is managed by National Highways regional teams. Identify which region covers the section of motorway or trunk road affected by your works. Contact the relevant regional team as early as possible in your planning process. Early engagement helps avoid delays and design rework later.
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2. Prepare your design submission
Prepare full design drawings in accordance with DMRB standards. Your submission must include a design statement explaining the scope and purpose of the works, detailed design drawings to the appropriate DMRB standard, a traffic management proposal complying with Chapter 8 Part 2 and National Highways specifications, a programme of works showing phasing and duration, and a safety risk assessment. For works involving structures (bridges, gantries, retaining walls), you must also apply for technical approval under BD 2 (DMRB Technical Approval of Highway Structures) before finalising your design.
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3. Submit traffic management proposals
All works on the SRN require approved traffic management. Your traffic management design must comply with Chapter 8 Part 2 of the Traffic Signs Manual and National Highways specifications. All traffic management operatives must hold National Highways Sector Scheme 12D qualification, which is mandatory for the strategic road network. Submit your traffic management proposal as part of your overall application.
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4. Book road space
All planned works on the SRN require a road space booking through National Highways. This coordination process ensures your works do not conflict with other planned works, events, or incidents on the network. Apply for your road space booking once your design and traffic management proposals are at an advanced stage. National Highways coordinates road space to minimise disruption to road users under its network management duty (Traffic Management Act 2004, Section 16).
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5. Obtain design approval
National Highways reviews your design submission for compliance with DMRB standards, safety, and impact on network operation. The review may result in approval, approval with conditions, or a request for amendments. Do not begin any works until you have received written approval. The applicant pays National Highways' reasonable costs for the design review, inspection, and supervision of works.
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6. Carry out works under supervision
Once approved, carry out the works in accordance with the approved design, traffic management plan, and programme. National Highways will inspect and supervise the works. Any changes to the approved scope, design, or traffic management must be agreed with National Highways before implementation. Working outside the approved scope is treated as unauthorised works.
Penalties for unauthorised works
Carrying out works on a trunk road or motorway without National Highways approval is a criminal offence under Section 175(2) of the Highways Act 1980. National Highways may also require the removal of any unauthorised works at the offender's expense under Section 175(3).
Beyond the criminal offence, unauthorised works on the SRN can result in significant costs for the contractor, including the cost of removing and reinstating works, compensation for any damage to the highway, and potential civil liability if the unauthorised works contribute to an accident.
What to do next
Once you have obtained National Highways approval:
- Check traffic management qualifications - all operatives on the SRN must hold National Highways Sector Scheme 12D. Verify registrations before work begins
- Coordinate with the local highway authority if your works also affect local roads adjacent to the SRN. You may need separate permits from the local authority for those elements
- Review reinstatement standards - reinstatement on the SRN must comply with both SROH and MCHW specifications, which may exceed the standard required for local roads
- Plan for night working if National Highways requires works to be carried out during off-peak hours. Most lane closures on motorways must take place at night
For works on local roads (not the SRN), see Highway works and street works permits. For traffic management signing requirements applicable to all road types, see Set up traffic management for road works.