Section 278 works: process, bond and realistic timescales
A section 278 agreement usually takes longer than the planning application that required it. Here is the sequence, the costs beyond the works, and where programmes slip.
A section 278 agreement is the mechanism by which a developer pays for and builds works in the public highway, and on most schemes it runs longer than the planning application that required it. Technical approval of the design, a legal agreement, a surety bond, road space booking and a defects period after completion all have to happen in sequence. Budget a year from first submission to final certificate on anything involving a new junction, and treat that as an optimistic starting point rather than a plan.
The agreement itself is made under section 278 of the Highways Act 1980. Adoption of new streets inside the site is a separate matter under section 38, and the two are frequently confused at the point where a site access meets an estate road.
When works in the highway are required
Any alteration to the adopted highway needs the highway authority's consent, and planning permission does not provide it. A permission granted with a condition requiring an access to be formed is a permission you cannot lawfully implement until the highway agreement is in place.
The common triggers are a new or widened vehicular access, changes to a junction including signalisation or a right turn lane, alterations to footway levels and crossings, new pedestrian crossings, traffic calming, bus stop relocation, changes to on-street parking arrangements, and new street lighting or drainage connections. A simple domestic dropped kerb is handled under a different and much shorter procedure.
Where the road is a trunk road or motorway, the highway authority is National Highways rather than the county or unitary council, and access onto the strategic road network engages its own policy and a different approval route.
Technical approval and the design check
Technical approval is the stage that consumes the programme. The highway authority reviews your detailed design against its own standards, the relevant national design standards, and its adoption requirements.
Expect the submission to cover geometric design with visibility splays and swept paths, drainage design including outfall agreement and any connection consents, street lighting design with photometric calculations, structural design for any retaining wall or headwall, materials and construction details matched to the authority's specification, and a signing and lining scheme.
Authorities review in rounds. A first submission almost never passes, and a comment list of thirty items is ordinary rather than a sign of failure. What shortens the process is a pre-submission meeting, early agreement on the drainage outfall, and using the authority's own standard details wherever possible instead of a consultant's house style.
Road safety audits and their stages
Road safety audit is a separate discipline from design review and is carried out by an independent team. Under the national standard it runs in stages: at preliminary design, at detailed design, shortly after opening, and a later monitoring stage.
Two practical points matter. The audit team must be independent of the designer, so budget for a separate appointment. And audit recommendations have to be formally responded to, with each one either accepted or rejected in writing with reasons, and the authority signs off that exception report. Leaving the audit to the end of technical approval guarantees a rework loop, because a stage 2 recommendation can change the geometry you have just had approved.
The agreement, fees, bond and commuted sums
The legal agreement follows technical approval, and it carries costs beyond the works themselves.
| Item | What it covers |
|---|---|
| Design check fee | The authority's cost of reviewing your submission |
| Legal fee | Preparing and completing the agreement |
| Supervision or inspection fee | Site inspection during construction, usually a percentage of works value |
| Surety bond | Security for the authority to complete the works if you do not |
| Commuted sum | A payment towards future maintenance of items the authority would not otherwise adopt |
The bond is the item developers underestimate. It is security, provided by a bank or a surety company, sized on the estimated cost of the works plus an allowance for the authority's own costs of stepping in, and it ties up facility or cash until the final certificate. Ask what percentage the authority applies and whether it accepts a bond from your chosen provider before you assume the figure.
Commuted sums arise for things like non-standard surfacing, street trees, signal equipment and structures. They are negotiable in scope and rarely in principle.
Road space, permits and statutory undertakers
Approval to build is not permission to occupy the road. Works on the highway need a permit or a notice under the authority's coordination arrangements, with lead-in times, and heavily trafficked routes have restricted working windows or embargo periods.
Statutory undertakers are the other programme risk. Any diversion of gas, water, electricity or telecoms apparatus runs on the utility's timescale, not yours, and the sequence of estimate, acceptance, design and works takes months. Order those estimates at the same time as you start technical approval rather than after it, because a cable diversion discovered late will move everything.
Temporary road closures and street works during construction sit alongside this, and the same coordination team usually handles both, so a single relationship with that team is worth cultivating.
Inspection, defects and the maintenance period
Once construction starts, the authority inspects. Its inspector can stop works, reject materials and require rework, and the contract between you and your contractor needs to reflect that.
On substantial completion the authority issues a provisional certificate, and a maintenance period begins during which you remain responsible for defects. Twelve months is the usual length. At the end of it, assuming the defects are made good, the authority issues a final certificate, the works become its maintenance responsibility, and the bond is released.
Two things commonly delay the final certificate. Outstanding snagging that nobody has chased because the site team has moved on, and the as-built records, including drainage CCTV surveys and lighting test certificates, which the authority will not sign off without.
Programme allowances that actually work
- Start highway design discussions at pre-application, before the planning layout is fixed, because access geometry constrains the layout more than the reverse.
- Submit for technical approval as soon as permission is granted, and assume at least two full rounds of comments.
- Appoint the road safety audit team early and run stage 1 alongside the planning application.
- Order statutory undertaker estimates in parallel with technical approval.
- Instruct solicitors on the agreement while technical approval is still running, since the legal and technical tracks can overlap.
- Arrange the bond before you need it, and confirm the authority accepts your provider.
- Add the maintenance period to the end of your programme, because a site is not finished when the road opens.
The transport evidence that supported the application should feed this process rather than sit apart from it. A Transport Assessment that has already agreed junction capacity and access geometry with the highway authority removes most of the argument at technical approval, and the Construction Traffic Management Plan should be written knowing what the permit regime on that road allows. Where the scheme includes internal streets for adoption, what highway officers want to see on shared surfaces applies from the first sketch layout.
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 is the difference between a section 278 and a section 38 agreement?
Section 278 of the Highways Act 1980 covers works a developer carries out to the existing adopted highway, such as a new access or junction alteration. Section 38 covers the adoption of new streets built inside a development site. Most residential schemes with an estate road need both, and the interface between them needs designing.
Why does the highway authority need a bond?
It is security so the authority can complete the works if the developer does not. The bond is provided by a bank or surety company, sized on the estimated cost of the works plus an allowance for the authority's own costs of stepping in, and it remains in place until the final certificate is issued after the maintenance period.
How long does technical approval take?
Longer than most programmes allow. Authorities review in rounds and a first submission rarely passes, so assume at least two full comment cycles. What shortens it is a pre-submission meeting, early agreement on the drainage outfall and using the authority's own standard details rather than a consultant's house style.
Who carries out the road safety audit?
An independent team, separate from the designer, appointed and paid for by the developer. The audit runs in stages at preliminary design, detailed design, shortly after opening and later for monitoring. Each recommendation must be accepted or rejected in writing with reasons, and the authority signs off that exception report.
When is the bond released?
After the maintenance period ends and the authority issues the final certificate. The maintenance period usually runs twelve months from the provisional certificate. Release is commonly delayed by outstanding snagging and by missing as-built records such as drainage CCTV surveys and street lighting test certificates.
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.