National Highways or the local highway authority

Whether National Highways or the local highway authority responds to your application depends on which network your traffic reaches. National Highways operates the strategic road network in England, the motorways and the trunk A roads. Everything else, including the road your site actually fronts onto in most cases, belongs to the local highway authority: a county council, a unitary authority, or in London the boroughs alongside Transport for London for its own network.

The distinction matters because the two bodies ask for different evidence, apply different standards, and have different powers. One of them can stop your permission being issued.

Which network each body is responsible for

National Highways is the highway authority for the strategic road network. That is a defined set of routes, and being a busy dual carriageway does not put a road on it: plenty of major A roads are local authority roads, and some quiet trunk roads are on the strategic network.

Check the status of every road in your assessment rather than assuming. The junction two miles away that your traffic will pass through may be the one that brings National Highways into the process, even where your access is onto a residential street.

Local highway authorities cover the rest, and they hold the local standards that shape the layout: parking standards, access design, visibility requirements, refuse vehicle tracking, cycle parking, adoption criteria and the design guide the estate roads have to follow.

When National Highways is consulted

The council must consult National Highways where development could affect the strategic road network, in the circumstances set out in the development management procedure order. In practice authorities consult where a site is close to a strategic junction, where the development is large enough to distribute traffic onto the network, or where an access would be taken from a trunk road.

Its published policy on the strategic road network and sustainable development sets the approach. In outline: it supports development that does not compromise the safe and efficient operation of the network, expects sustainable travel measures to be considered first, and looks for mitigation only where the residual impact on the network is material. It is not looking for a contribution from every scheme in the district.

That last point is worth holding onto during negotiation. An impact of a handful of movements in the peak hour at a junction operating within capacity is not a reason for mitigation, and the appropriate response is to demonstrate that rather than to offer a contribution.

Directions and their effect

The power that changes the dynamic is the direction.

National Highways, acting on behalf of the Secretary of State, can issue a direction requiring the local planning authority not to grant permission for a specified period while the effect on the strategic network is considered. It can also direct that permission be refused, or that specified conditions be imposed.

Three consequences follow.

First, the determination period becomes largely irrelevant while a holding direction is in force, and an appeal against non-determination will not help.

Second, the council cannot simply resolve to approve against the direction, so a committee resolution to grant does not end the matter.

Third, the way out is technical rather than political. The direction lifts when National Highways is satisfied, which means agreeing the assessment methodology, the mitigation if any, and the conditions. That is a negotiation with engineers, and it moves at the speed of their review.

The evidence each body asks for

They overlap less than people expect.

National Highways will focus on:

1. Trip generation, distribution and assignment onto the strategic network, with the growth factors and assessment years agreed in advance.
2. Committed development included in the future year case.
3. Junction capacity assessment at the affected strategic junctions, with model inputs and outputs provided rather than summarised.
4. Safety, usually including collision records over a recent period for the relevant links and junctions.
5. Any proposed mitigation, designed to its standards, with a deliverability and funding position.

The local highway authority will focus on:

1. The access itself: geometry, visibility splays, gradient, forward visibility and whether vehicles can enter and leave in forward gear.
2. Internal layout: road widths, radii, turning for refuse and emergency vehicles, and adoption standards.
3. Parking, against the local standard, with cycle and accessible provision.
4. Servicing and delivery arrangements.
5. Sustainable transport: footway and cycle connections, bus stop infrastructure, and a travel plan.

Whether the work is packaged as a Transport Statement or a fuller Transport Assessment depends on scale, and the scoping should be agreed with both bodies rather than assumed from a threshold table. Where measures are secured, a Travel Plan is usually the mechanism, and both authorities may want to be named in the monitoring arrangements.

Where both respond to one application

This is the normal position on anything larger than an infill site, and the way to manage it is one document with agreed inputs.

Agree trip rates, the survey period, growth factors, assessment years and the committed development list with both bodies before modelling. Where they disagree on an input, get that resolved in the scoping stage rather than presenting two sets of numbers. Then write a single assessment with distinct chapters for the local network and the strategic network, so each consultee can find its own material.

On majors of 150 or more dwellings, or larger non-residential floorspace, Active Travel England is also a statutory consultee, applying its own assessment of walking, cycling and wheeling provision. That is a third set of comments on the same drawings, and its interests sometimes pull against a highway authority's preference for vehicle capacity at an access.

Illustrative example: a 180-dwelling site accessed from a B road managed by the county council, 900m from a trunk road roundabout. The county is concerned with the access geometry, a pedestrian crossing, estate road adoption and parking numbers. National Highways is concerned with the 40 or so peak hour movements arriving at the roundabout and asks for capacity modelling with committed development included. Active Travel England comments on the cycle connection to the town centre. One assessment covers all three, with agreed trip rates and a single future year case, and the roundabout modelling shows spare capacity so no strategic mitigation is sought.

Engaging with each before submission

Do this separately, because they operate differently.

The local highway authority usually takes pre-application enquiries through the council's own service, or directly where the county is a separate body. A meeting with a plan, a swept path drawing and a parking schedule resolves most of the layout questions early.

National Highways takes pre-application engagement through its own planning or spatial planning team, and the thing to ask for is agreement on scope: which junctions, which years, which growth factors, what safety data. Getting that in writing before modelling starts is the single most effective way to avoid a holding direction later, because most directions arise from disagreement about methodology rather than about the conclusion.

Where a site is in London, add Transport for London for development affecting its road network or referable to the Mayor, and expect an approach weighted towards public transport accessibility and car-free development.

One habit worth adopting. Put the scoping correspondence in an appendix to the assessment. It shortens the consultee's review, and it makes it much harder for a late objection to be founded on an input that was agreed months earlier.

Enter your postcode on PlanScope to see which transport documents your site is likely to need before you commission modelling.

This is general guidance, not legal advice; check the position with your local planning authority, the relevant highway authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.