Road safety audit stages and when each one applies
A road safety audit asks one question: could this layout hurt somebody. Here is what each stage covers and why a Stage 1 audit belongs before the planning application.
A road safety audit is an independent check of the safety of a highway design, carried out by people who had no part in designing it, and it is usually required where your development builds or alters public highway under a section 278 agreement. It is not a transport assessment and it does not test capacity or policy compliance. It looks at one question: could this layout hurt somebody.
Most developers meet it late, when the highway authority attaches an audit requirement to a section 278 approval and the design is already fixed. Meeting it early costs far less, because audit findings that arrive after a planning permission has fixed the access position can force a fresh application.
What a road safety audit is and is not
The audit team reviews drawings, and later the built scheme, against safety considerations rather than against standards compliance. A design can comply with every dimension in the relevant standard and still attract an audit problem, because the audit asks how real drivers, riders and pedestrians will behave rather than whether the geometry is correct.
The output is a report listing problems and recommendations. Each problem describes the safety issue and who is at risk, and each recommendation suggests a way to remove or reduce it. The audit does not redesign the scheme and it does not have the final word. The overseeing organisation, usually the local highway authority for development-led works, decides what happens next.
Confusing the audit with a Transport Assessment causes real problems in programme. The assessment supports the planning application and deals with trip generation, distribution and junction capacity. The audit sits with the detailed highway design and runs on the engineering timeline.
The stages and what each covers
The staged process is set out in the national standard for road safety audit within the Design Manual for Roads and Bridges, which local authorities widely adopt for development-led works with their own local variations.
| Stage | When it happens | What it looks at |
|---|---|---|
| Stage 1 | Completion of preliminary design | Alignment, junction layout, the principle of the access |
| Stage 2 | Completion of detailed design | Signing, markings, lighting, drainage, visibility splays as detailed |
| Stage 3 | Completion of construction, before opening | The scheme as built, including a night-time visit |
| Stage 4 | After opening, using collision records | Whether the scheme is performing as expected in service |
Small schemes are often audited as a combined Stage 1 and 2, and some authorities require an interim audit where a design changes materially between stages. Stage 3 is the one people forget to programme, and it has to happen before the road opens to traffic.
Who can audit and independence requirements
Independence is the point of the exercise. The audit team must not have been involved in the design, and on larger or higher-risk schemes the authority will expect complete organisational separation rather than a different team in the same office.
The team is normally a team leader and at least one team member, both with road safety audit training and documented experience, and the team leader carrying more of both. A police road policing observer and a local authority maintenance officer are often invited to the site visit, which is worth encouraging because they know the road.
Ask the highway authority for its own requirements in writing before appointing anyone. Authorities differ on whether they will accept an auditor from the same consultancy as the designer, and finding out after the report is issued is an expensive way to learn.
The brief and the material provided
The audit brief decides the quality of the audit. It should include the drawings at the relevant stage, the design standards and any departures from them, the traffic data, collision data for the surrounding network, details of the surrounding land uses, and any constraints the designer worked around.
Collision data matters more than anything else in the pack. Personal injury collision records for the study area, usually for the most recent five-year period available, let the team see the existing pattern and test whether the proposal makes it worse. Using that data properly is a discipline in itself, and our note on personal injury collision data covers the traps.
Say plainly in the brief what the scheme is for and what has already been agreed with the authority. An audit team that does not know a junction layout was fixed by a committee resolution will recommend changing it.
Designer responses and exception reports
Every problem in the audit report needs a written response from the designer. There are three honest answers: accept and amend the design, accept the problem but propose different mitigation, or reject the recommendation with reasons.
Rejection is legitimate and common. The mechanism is an exception report setting out why the recommendation is not being adopted, what alternative measures are proposed if any, and the residual risk. The overseeing organisation then decides. What is not legitimate is silence, or a response that restates the design without engaging with the risk.
Keep the paper trail. The audit report, the designer response, the exception report and the authority's decision form a package that gets looked at again if there is an incident, and a reasoned record is what protects everyone involved.
Timing against the planning and highway agreements
Sequence the work like this:
- Agree the access principle with the highway authority before the planning application, and commission a Stage 1 audit on the preliminary access design where the authority expects one
- Submit the application with the access layout the audit supports, not the layout drawn before it
- Detail the design for the section 278 agreement, then commission the Stage 2 audit
- Build, then commission the Stage 3 audit before the road opens, allowing for a night visit and for remedial works
- Provide for Stage 4 monitoring where the authority requires it in the agreement
The step people skip is the first one. A Stage 1 audit that recommends moving an access by 15 metres is a drawing change before submission and a fresh planning application afterwards.
How audit findings change a layout
The recurring recommendations are predictable: visibility obstructed by proposed planting or a boundary wall, a pedestrian crossing point placed where people will not use it, a right-turn manoeuvre without adequate waiting space, refuse and delivery vehicles reversing across a footway, and street lighting that ends at the site boundary and leaves a dark section on the approach.
Design them out early and the audit becomes a short document. Landscape proposals in particular need checking against visibility splays before they reach the planning drawings, because a landscape plan approved by condition can quietly reintroduce a problem the audit removed.
Road safety audits are prepared by independent auditors and are not one of PlanScope's 66 report types. What PlanScope can draft is the supporting planning documentation around the highway work, including the transport statement and construction traffic material. Browse all 66 report types to see what your scheme needs, and send anything technical for professional review before submission.
This is general guidance, not legal advice; check the position with 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
What are the road safety audit stages?
Stage 1 follows preliminary design and looks at alignment and the principle of the access. Stage 2 follows detailed design and covers signing, markings, lighting and visibility as detailed. Stage 3 happens after construction and before opening, including a night visit. Stage 4 uses collision records after opening. Small schemes are often audited as a combined Stage 1 and 2.
Is a road safety audit the same as a transport assessment?
No. A transport assessment supports the planning application and deals with trip generation, distribution, mode share and junction capacity. A road safety audit is an independent safety review of a highway design, sitting with the detailed engineering and usually required under a section 278 agreement. They run on different timelines and answer different questions.
Who can carry out the audit?
A team independent of the designer, normally a team leader and at least one team member, both with road safety audit training and documented experience. On larger schemes authorities expect organisational separation rather than a different team in the same office. Ask the highway authority for its own requirements in writing before appointing anyone.
Can I reject an audit recommendation?
Yes, through an exception report. It sets out why the recommendation is not being adopted, what alternative measures are proposed and the residual risk, and the overseeing organisation then decides. Rejection with reasons is legitimate and common. Silence, or a response that restates the design without engaging with the risk, is not.
When should the first audit happen?
Before the planning application where the highway authority expects a Stage 1 audit on the access design. A Stage 1 recommendation to move an access is a drawing change before submission and a fresh planning application afterwards, so the cost of doing it early is very small compared with the cost of doing it late.
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.