Technical approval or a road safety audit stage
Technical approval and road safety audit are separate gates inside a section 278 or section 38 agreement. They have different approvers, different standards and different programme risks.
Highway technical approval and a road safety audit are two separate gates on the same access design, and a scheme can clear one while failing the other. Technical approval is the highway authority's check that your detailed design is buildable, drainable, maintainable and compliant with its standards. A road safety audit is an independent review, carried out by people who had no hand in the design, of whether the built layout will cause collisions. Both normally sit inside a section 278 or section 38 agreement under the Highways Act 1980, and on a scheme of 50 or more units they are the two items most likely to slip a programme by a quarter.
What technical approval actually checks
Technical approval is a documentary process. The authority, or National Highways on the strategic road network, works through your drawings and calculations and issues approval in stages rather than in one go.
For highway structures the route begins with an Approval in Principle. That document sets out the form of the structure, the design standards and loading, the materials, the design life and the proposed check category. Bridges, culverts, gantries and retaining walls above a modest retained height (commonly taken as 1.5 m) all fall into this category. The higher check categories bring in an independent checking engineer with no commercial link to the designer, which costs money and takes weeks.
Everything else is checked against the authority's own specification and the relevant parts of the Design Manual for Roads and Bridges. In practice that means pavement construction depths and subgrade assumptions, positive drainage and the outfall you intend to use, street lighting design, tactile paving layouts, swept path analysis for the largest vehicle expected, visibility splays measured on the ground rather than off a title plan, signs and markings prescribed by the Traffic Signs Regulations and General Directions 2016, and the materials schedule. Where you propose anything non-standard, a block paved crossing or a feature tree in a verge, expect a request for a commuted maintenance sum.
Approval ends with the authority confirming that the design may be built. It says nothing about whether the design is safe to use.
What a road safety audit checks, and who is allowed to do it
The audit is a safety review of the layout itself, conducted to the road safety audit standard in the Design Manual for Roads and Bridges (GG 119). The team looks at the drawings, the collision record for the surrounding network and, from Stage 2 onwards, the site, and writes up problems with recommendations to remove or reduce them.
Independence is the point of it. The audit team leader and team member must have no involvement in the design of the scheme, must meet stated experience and training requirements, and work from a written audit brief agreed with the overseeing organisation. The team is also given collision data for the study area, normally the most recent three years of personal injury records, so that an existing pattern is not repeated by the new geometry.
Auditors do not redesign. They identify a problem, say why it matters and suggest a direction. Whether that direction is adopted is someone else's decision.
The stages and where each one lands
| Stage | Trigger point | What it bites on |
|---|---|---|
| Feasibility (optional) | Options appraisal | Choice of access location and junction type |
| Stage 1 | Completion of preliminary design | Geometry, visibility, junction form, land take |
| Stage 2 | Completion of detailed design | Signs, markings, lighting, drainage gullies, kerb lines |
| Stage 3 | Completion of construction, before opening | What was actually built, in daylight and after dark |
| Monitoring | After opening | Collision record against the audited layout |
On small section 278 schemes the authority will often accept a combined Stage 1 and 2 audit. That saves a fee and loses the chance to fix a geometric problem before the detailed design is paid for, so it is a false economy on anything with a right-turn lane or a signal alteration.
Stage 3 is the one developers forget to programme. It happens after construction and before the road is opened to traffic, and a Stage 3 problem can mean cutting into a finished surface.
Who commissions, who signs and who carries the risk
On a developer-funded scheme the developer pays for both processes, but neither is the developer's to approve. Technical approval is granted by the highway authority. The audit brief is agreed by the overseeing organisation, which is the authority for a local road and National Highways where the works touch the strategic network. Deciding which of those two bodies you are dealing with should happen before any design work starts, because the standards, the approval route and the appetite for departures all differ, and our note on whether National Highways or the local highway authority is the relevant body sets out how to tell.
The designer signs the design. The checker signs the check. The audit team signs the audit report. The authority signs the technical approval and, later, the certificate of completion that releases the bond. Four signatures, four different liabilities, and the developer sits underneath all of them holding the programme.
The designer's response and agreed exceptions
An audit report is not binding by itself. The design organisation prepares a designer's response addressing every problem raised, accepting the recommendation, proposing an alternative that deals with the problem another way, or rejecting it.
A rejection has to be justified in writing as an exception, and the exception is approved by the overseeing organisation rather than by the designer. Authorities keep those records. If a collision later occurs at the location an auditor flagged, the exception is the first document anybody asks for.
Illustrative example: on a 60-unit scheme taking access from a classified road, a Stage 1 audit flags forward visibility to the new priority junction around an existing bend. The designer proposes moving the access 15 m east rather than removing the hedgerow the auditor had in mind. The authority accepts the alternative, but the revised access no longer matches the site plan attached to the permission, so a variation application follows. Two months, and a fee, for a problem that cost nothing to find.
How both processes interact with your planning conditions
Most permissions handle highway works with a Grampian condition: no development may begin, or no dwelling may be occupied, until the access works have been approved and constructed under an agreement with the highway authority. The condition is drafted on the assumption that technical approval and the audit will be straightforward.
The trap is the approved drawings condition. Your planning drawing showed an indicative access. The technically approved drawing shows a different radius, a longer right-turn pocket and a relocated gully. If the difference is visible on the approved plan you are into a section 96A non-material amendment or, where the change is more than trivial, a section 73 application to vary the condition. Either way you need the time, and a transport case to go with it, which is why the access geometry in a Transport Assessment should already be an auditable design rather than a sketch.
Construction traffic is a separate strand. A Construction Traffic Management Plan condition is often discharged on the strength of routing and wheel wash detail, and it is usually quicker to settle than the section 278 agreement it depends on.
Where the delay usually comes from
Five things account for most of it, and none of them are the audit itself.
- Appointing the audit team late, so Stage 1 lands after the planning drawings are fixed.
- Visibility splays that need land or vegetation control outside the application boundary.
- A drainage outfall that needs the sewerage undertaker's consent, or a highway drain the authority will not accept more flow into.
- A traffic regulation order for waiting restrictions or a speed limit change, which carries its own statutory consultation and can be objected to.
- Legal drafting of the agreement, bonds and commuted sums, which runs on the authority's legal team's timetable rather than yours.
Programme them backwards from first occupation and the sequence usually works. Programme them forwards from planning permission and you will be waiting on a traffic regulation order while the show homes stand empty. If you are putting the evidence base together and want to see which supporting documents a site of this type is likely to need, you can work through the report list before you commit to any consultant fees.
This is general guidance, not legal advice, so check the position with your local highway authority, your local planning 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.
Frequently asked questions
Is a road safety audit a legal requirement for a section 278 scheme?
It is not a statutory requirement in itself, but highway authorities almost always impose it as a term of the section 278 agreement, and National Highways applies the road safety audit standard in the Design Manual for Roads and Bridges to works on the strategic road network. In practice you will not get a signed agreement without one, so treat it as mandatory.
Can my transport consultant carry out the road safety audit on my own scheme?
No. The audit team must be independent of the design team, with no involvement in producing the scheme being audited, and the team leader and team member have to meet set experience and training requirements. Firms large enough to separate the two functions sometimes do both, but the authority has to accept that separation in writing.
Do technical approval and the audit happen before or after planning permission?
Usually after, because a Grampian condition ties them to the start of development or to occupation. The problem is that a Stage 1 audit can force a change to the access geometry you already have permission for. Commissioning a Stage 1 audit before the application is submitted costs comparatively little and avoids a variation application later.
What happens if I reject an audit recommendation?
You record it as an exception in the designer's response, with the reasoning, and the overseeing organisation decides whether to approve the exception. It is a normal part of the process rather than a failure. The record is kept, and it is the first document examined if a collision later happens at that location.
Which approvals release the bond at the end?
The highway authority issues a certificate once the works are complete, any Stage 3 audit items are resolved and the maintenance period has run. Commuted sums for non-standard materials are normally paid before that point. Check the sequence written into your agreement, because the wording differs between authorities.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.