Who should write a transport assessment or statement

No statute says who may write a transport assessment, which is why the question of who can write a transport assessment is answered by the highway authority rather than by a register. The authority agrees the scope with you first, and it then expects the document to come from someone who can defend the trip rates, run or commission the junction modelling, and stand behind the mitigation. Get the scoping agreement in place and the competence question largely answers itself, because the scope tells you which skills the job needs.

Two authorities may be involved. The local highway authority for most schemes, and National Highways where the strategic road network is affected.

What the highway authority expects from the author

Highway authorities judge transport evidence on three things: whether the method matches what was agreed, whether the inputs are traceable, and whether the author has done this before.

In practice that means a transport planner with demonstrable experience of schemes of the same type and scale, access to the trip generation data the authority accepts, and either in-house junction modelling capability or a named sub-consultant for it. Authorities rarely ask for a specific qualification in writing. They do form a view quickly, and a document that misapplies a trip rate or cites a superseded design standard loses credibility it is hard to recover.

Scale changes the expectation. A Transport Statement for a small residential scheme is a short document that a competent generalist can produce. A Transport Assessment for a scheme generating hundreds of peak hour trips, with junction capacity modelling and a mitigation package to be secured by a highway agreement, is specialist work.

Chartered membership routes for transport planners

Several recognised routes exist, and they signal different things.

The Chartered Institution of Highways and Transportation offers chartered status in highways and transportation and is the membership most often seen on transport assessments. The Chartered Institute of Logistics and Transport covers transport and logistics more broadly and is common among those working on freight and servicing. The Institution of Civil Engineers covers the engineering design side, including highway geometry and drainage. The Transport Planning Society operates a transport planning professional qualification assessed against defined competencies, which is the closest thing in this field to a transport planning specific credential.

None of those is a licence to practise. What they tell you is that the person has been assessed against a competency framework by peers, and that there is a professional body with a code of conduct behind them. Checking the claim takes a couple of minutes, using the approach in our note on checking a professional institute register.

Experience is the input that matters more. A planner who has taken three similar schemes through the same highway authority knows what that authority will ask for, and that knowledge is worth more than a letter after a name.

Access to trip generation databases and their licences

Trip rates are the foundation of the whole document, and the recognised source is a subscription database of surveyed sites that practitioners licence rather than buy outright.

That has two consequences. A consultant without a licence cannot produce a defensible rate and will either borrow one or cite a figure without provenance, both of which an authority will reject. And the full output, showing the site selection criteria, the filters applied and the database version, has to be appended so the authority can reproduce the query.

Check five things in any trip rate section:

1. The land use category chosen, and whether it matches the proposal in substance.
2. The filters: region, location type, survey date range, site size range and parking provision.
3. The number of surveyed sites the rate is drawn from, since a rate from two sites is weak.
4. Whether person trips or vehicle trips are reported, and the conversion used between them.
5. Whether the rate has been adjusted, and on what basis.

Local authority data sometimes beats the database. Where the authority holds its own surveys of comparable developments in the district, using them is both more persuasive and easier to defend.

Junction modelling competence as a separate skill

Capacity modelling is a distinct discipline from transport planning, and plenty of competent transport planners do not do it themselves.

Priority junctions and roundabouts, signal junctions and microsimulation networks each use different software and different skills, and authorities often specify which they will accept. The deliverable is not the result but the model: the authority or its consultant will want the model files, the validation against observed queues and delays, the saturation flow assumptions, the growth factors applied and the assessment years.

Model validation is where submissions fall over. A base model that does not reproduce the queues people actually see on the ground cannot support a conclusion about the future, and an authority that has sat in that queue will say so. Build in time for the authority's audit of the model, because it is frequently the longest item in the determination period.

Agree the modelling scope in writing: which junctions, which peak periods, which assessment years, which growth source and which committed developments.

Road safety audit competence and why it is separate

A road safety audit must be carried out by a team independent of the design team, with no involvement in the design being audited. That independence is the whole point of the process and it is set out in the national design standards for road safety audit.

So the consultant who designed your access cannot audit it, and a report that presents a safety audit signed by the design team will be sent back. Audit team members also need specified recent experience and training, and the stages of audit are defined, with preliminary design, detailed design, completion and post-opening monitoring stages.

Note that a road safety audit is a highway engineering deliverable rather than a planning report, so budget for it separately and programme it against the highway agreement rather than against the planning submission.

Scoping the assessment with the authority first

National guidance expects the need for and the content of a transport assessment to be established through pre-application discussion with the highway authority. Treat that as a document rather than a conversation.

The scoping note should record the study area, the assessment years including the opening year and a future year, the peak periods, the junctions to be modelled, the growth factors and their source, the committed development list, the trip rate source and filters, the modal split assumptions, the accident data period and source, the parking standards to be applied, and the walking and cycling assessment method. Get it signed off by the authority's officer by email, and append it to the submitted assessment.

That one document prevents the most expensive failure mode, which is a submitted assessment the authority rejects because it modelled the wrong junctions. Where the scheme is large enough, Active Travel England is a statutory consultee for major applications above the thresholds set for it, and its interests should be scoped in at the same time.

A Travel Plan is normally a separate deliverable with its own targets and monitoring, and it should be scoped alongside rather than bolted on at the end.

Reviewing a draft before submission

Read the draft against the scoping note line by line. Then run these checks.

Do the trip rates in the tables match the appended database output. Does the committed development list match the authority's own list, which you can ask for. Are the accident data years stated and recent, and has the analysis looked at patterns rather than totals. Do the junction results include the base year validation. Does the mitigation have a deliverability route, meaning land ownership and a highway agreement mechanism rather than a line on a drawing. And does the conclusion follow from the modelling rather than from the applicant's preference.

Finally, check the author details. Name, qualifications, membership and the firm, with a statement of the scope and limitations. A document nobody has put their name to is a document nobody will defend at appeal. Reviewers for technical drafts can be found through the professional directory, and the wider approach to assessing a consultant's experience is in our note on reading a consultant CV for real competence.

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.