Transport planner competence and trip rate data licensing
Trip generation work depends on a licensed database held by the organisation, not the individual. Check the licence, then the modelling, then the letters after the name.
A Transport Assessment is one of the few supporting documents where the author's access to licensed data matters as much as their qualifications. Trip generation work on most English schemes relies on a subscription database of surveyed sites, and the licence is held by the organisation rather than the individual, so an unlicensed consultant cannot lawfully produce the trip rates the highway authority expects to see.
That is the practical competence question to ask before anything about letters after a name. Start with the licence, then the modelling, then the membership.
What a Transport Assessment asks of its author
The document has to do four separate technical jobs. Establish the baseline, including traffic counts, collision records and public transport accessibility. Forecast the trips the development will generate and distribute them onto the network. Test the effect at the junctions where the increase is material. And set out access design, servicing, parking and any mitigation.
Each of those draws on different skills. Baseline work is largely data handling. Trip generation is database work plus judgement about site comparability. Junction capacity testing is modelling. Access design is highway engineering governed by design standards. One person can hold all four, but on a scheme of any size the work is split, and the useful question is which named individual did which part.
The threshold for needing the full assessment rather than a shorter statement is set locally, with the Planning Practice Guidance on travel plans, transport assessments and statements as the framework. PlanScope's own recommendation engine flags a Transport Assessment at 50 or more units or 2,500 m² or more, though the authority's validation list and adopted parking standards take precedence over any general threshold.
Professional membership routes and what each signals
| Route | Letters | What it tells you |
|---|---|---|
| Chartered Institution of Highways and Transportation | MCIHT, FCIHT | Broad highways and transport competence, assessed by peer review |
| Chartered Institute of Logistics and Transport | CMILT | Transport and logistics, strong on servicing and freight |
| Transport Planning Professional | TPP | Specific assessed competence in transport planning practice |
| Institution of Civil Engineers | MICE, CEng | Engineering design of the access and structures |
None of these is a licence to practise, because transport planning is not a protected activity. They are evidence of assessed competence, and the Transport Planning Professional qualification is the closest thing to a direct match for the work in a Transport Assessment.
What matters more on a contested scheme is recent local experience. A modeller who has had a scheme through the same highway authority in the last two years knows which assumptions that authority accepts, and that saves more time than any qualification.
Licensed trip rate data and who may use it
Trip generation rates for English schemes are normally drawn from a national database of surveyed development sites, accessed under a subscription licence. Three things follow.
The licence sits with the subscribing organisation, and outputs are produced under it. A consultant without a subscription is either buying outputs from someone who has one, in which case say so, or using rates from another source, which the highway authority will question.
Site selection is where judgement enters. The database returns dozens of candidate surveys, and the analyst filters by land use category, size range, location type, parking provision, survey date and day of week. Two competent analysts filtering the same database can produce trip rates that differ by a third, entirely legitimately, so the report must show the selection criteria applied and the sites included and excluded. A Transport Assessment that reports a trip rate without the site selection appendix cannot be checked.
Survey age is the recurring argument. Travel patterns for some land uses shifted after 2020, and a rate built from 2015 surveys of an office park is not obviously applicable now. State the survey date range you accepted and why.
Junction modelling competence
Capacity testing uses established models: one family for priority junctions and roundabouts, another for signal controlled junctions, and microsimulation where a corridor or a network effect has to be tested rather than a single node. Each has a licence, each has conventions, and each produces outputs that are only as good as the geometry and flow inputs.
The competence signals worth asking about:
- Which model was used and why that one for this junction type.
- Whether the geometric inputs were measured on site or scaled from a drawing.
- Whether the base model was validated against observed queues and delays, and against what data.
- Whether the future year flows include committed development, and which permissions were counted.
- Whether the model files will be released to the highway authority for audit.
Point five separates the serious from the rest. Highway authorities increasingly ask for the model files, and a consultant who declines is telling you something.
Road safety audit is a different discipline
A road safety audit is not part of a Transport Assessment and cannot be produced by the design team. It requires independence from the designer, and audit team competence is defined in the national highway standards by a combination of certificated audit training, current experience of auditing and, for a team leader, a minimum period of that experience.
Where a scheme includes a new or altered highway that will be adopted, the audit sits in the section 278 or section 38 process rather than in the planning application, though the planning submission should say that the stage 1 audit has been carried out or is programmed. Confusing the two is common and costs a round of consultation.
Where the highway authority reviews the work
The local highway authority reviews most schemes, and National Highways reviews anything affecting the strategic road network. Both may ask for the model files, the trip rate selection, the collision data extract and the survey data. Both have their own view on what constitutes a severe residual impact.
Agree the scope with them before commissioning, in writing, covering the study area, the assessment years, the growth factors, the committed development list, the survey dates and the junctions to be modelled. That scoping note costs least of anything in the exercise and is the one most often skipped.
Briefing the scope before you commission
Write the brief around the scoping note rather than around a document title. Name the junctions, the assessment years, the data sources, the model type, the deliverables and who will attend meetings with the authority. Ask for the trip rate site selection and the model files as deliverables, not as extras.
Then check the individual, not the firm. Ask who will do the modelling, what they have taken through this authority, and whether their competence is recent rather than historic. Survey data has a shelf life too, so check whether a survey is still valid before you rely on counts from a previous application.
PlanScope's professional directory is the route for having a draft reviewed and signed off, and the 66 report types by category show which transport documents usually travel together on a major application. A Transport Assessment is a report councils expect a suitably qualified transport planner to author, and professional review is strongly advised.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.
Enter your postcode on PlanScope to see which reports your site is likely to need. 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 licence needed to produce trip rates?
In practice yes. Trip generation on most English schemes comes from a subscription database of surveyed development sites, licensed to the subscribing organisation rather than to an individual. A consultant without a subscription is either buying outputs from a subscriber, which should be stated, or using another source that the highway authority will want justified.
Which professional membership should a transport planner hold?
There is no protected title, so membership is evidence rather than authorisation. The Transport Planning Professional qualification maps most directly onto the work in a Transport Assessment, with chartered membership of the highways and transportation or logistics institutions also relevant. Recent experience of the same highway authority often matters more than the letters.
Why do two consultants produce different trip rates from the same database?
Because the analyst filters candidate surveys by land use category, size range, location type, parking provision, survey date and day of week, and those filters are judgement calls. Differences of a third are possible without anyone being wrong. That is why the report must include the selection criteria and the sites included and excluded.
Should the model files be shared with the highway authority?
Yes, and increasingly they are asked for. Sharing lets the authority audit the geometry, the flows and the validation rather than taking the outputs on trust, which usually shortens consultation. A consultant unwilling to release model files is worth questioning before you commission the rest of the assessment.
Can the designer carry out the road safety audit?
No. Independence from the design team is fundamental to a road safety audit, and audit team competence is defined in the national highway standards through certificated training plus current auditing experience, with a longer experience requirement for the team leader. The audit belongs to the highway agreement process rather than to the Transport Assessment.
What should a transport scoping note cover?
The study area, assessment years, growth factors, the committed development list to be included, survey dates, the junctions to be modelled, the model type for each and the deliverables. Agree it in writing with the highway authority before commissioning. It costs least of anything in the exercise and is the one most often left out.
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.