Who should write your Transport Assessment, and with what data

A highway authority reading a transport report is asking two questions before it reads a single number: who wrote this, and where did the trip rates come from. Neither has a statutory answer. There is no protected title for transport planning and no legal requirement that a Transport Assessment be prepared by a chartered professional. What exists instead is a set of expectations, and an authority that does not recognise the author or the data source will send the report back rather than argue with it.

For a developer, that translates into two procurement questions. Does the practice hold a current subscription to the trip rate database everyone in the room uses, and can the named author defend the site selection at a hearing.

What a highway authority expects from the author

Highway officers work through a mental checklist. It is rarely written down, and it is consistent across authorities.

The report should name an individual author, as well as the practice. It should show that the scope was agreed with the authority before the work started. It should present trip rates with the full selection criteria, so the officer can reproduce the query. And it should engage with the local network as it actually operates, including the junction that everyone in the area complains about.

Authorities also look for continuity. A report written by someone who has dealt with that authority before, and who understands its parking standards and its local transport plan, gets a shorter response than one written by a practice appearing for the first time.

Professional memberships and what they signal

The Transport Planning Professional qualification is the one most directly on point, because it tests transport planning practice rather than engineering or logistics. Membership of a body is not a guarantee of quality, and plenty of experienced transport planners hold no chartered status at all. What membership gives you is a code of conduct, a disciplinary route and a competence assessment someone else has carried out.

For a Transport Statement on a small scheme, an experienced author without chartership is usually fine. For a major application where the access arrangement will be argued at inquiry, the author needs to be someone who can stand up and be cross-examined.

Access to trip generation data and its licensing

The industry standard source is the TRICS database, and access is by subscription. That matters commercially, because a practice without a subscription is either buying data through a third party or using an alternative source, and both show in the report.

The database is only as good as the site selection. Good practice requires the assessment to record which land use category was used, which survey sites were included, the geographical and date filters applied, and why particular surveys were excluded. A report that presents a trip rate without that audit trail cannot be checked, and an officer who cannot check it will ask for a resubmission.

Licensing also constrains what can be published. Database outputs are provided under licence, and reproducing large extracts beyond what the licence permits is a copyright problem rather than a planning one. Summarise, cite the query parameters, and attach the standard output sheet.

Where the database has no suitable category, and that happens with unusual uses, the alternatives are a bespoke survey of a comparable site, census journey to work data for modal split, and the Department for Transport's published road traffic statistics for background flows. Say which you used and why.

Scoping discussions and who should attend

Scope the assessment before anyone counts a car. National guidance on travel plans, transport assessments and statements expects the scope to be agreed with the local highway authority, and a scoping note agreed in writing is the single most useful document in the transport file.

Who should be in the room:

• The transport planner who will write the report and sign it.
• The highway development management officer for the authority.
• National Highways, where the site could affect the strategic road network. Circular 01/2022 sets out how that body engages.
• Active Travel England, for major applications at or above its consultation thresholds.
• The local authority's public transport or travel plan officer, where a travel plan will be required.

Agree six things: the study area, the assessment years, the trip rate source and site selection, the committed developments to be included, the junction assessment methodology, and whether a Travel Plan is required. Record the agreement and attach it as an appendix.

Reviewing a transport report before submission

Read it as the highway officer will. Four checks catch most problems.

Check the trip rates against the land use. A retirement housing scheme assessed on general residential rates overstates trips, and a build to rent scheme assessed on suburban house rates understates them. The category matters more than the arithmetic.

Check the survey dates. Counts taken in August or in the week before Christmas are not neutral, and an officer will notice.

Check the collision data. Five years of personal injury collision records from the highway authority is the usual expectation, and the analysis should say what the pattern is rather than tabulating incidents without comment.

Check the parking evidence. Where the scheme relies on a parking stress argument, a Parking Survey using a recognised methodology, carried out overnight midweek and at a weekend and avoiding school holidays, is what an officer expects to see.

Where transport reports are sent back

The recurring reasons, in rough order of frequency:

1. No agreed scope, so the officer disputes the study area before reading the results.
2. Trip rate site selection not reported, or reported so thinly it cannot be reproduced.
3. Access junction shown in principle with no visibility splays, geometry or swept path analysis.
4. Committed development omitted, particularly a scheme the authority itself permitted last year.
5. Construction traffic ignored, with no routing, no wheel washing and no delivery management.
6. Travel plan offered as a document to be produced later, where policy requires it now.

Illustrative example: a 60-unit scheme where the assessment used a suburban residential category from surveys in towns with far lower public transport accessibility than the application site. Rerunning the query with an appropriate filter reduced the peak hour trip estimate materially, and the mitigation package fell away with it. This example is illustrative, and the point is the selection rather than the number.

One honest uncertainty: thresholds for when an assessment is needed rather than a statement are set locally, and authorities differ. Ask, rather than working from a national rule of thumb.

PlanScope drafts transport documents structured to UK planning policy, flagging survey inputs and trip rate queries for the transport planner to complete rather than inventing them. Councils usually expect a suitably qualified author for transport work, and professional review is strongly advised. See how professional review and sign-off works.

This is general guidance, not legal advice. Check the position with your local 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.