Travel plan targets and survey methodology that hold up
A travel plan target only works if someone can measure it later. Here is how to fix the baseline, the mode, the number and the date so the monitoring obligation can actually be discharged.
A travel plan target only works if someone can measure it later. That single test disposes of most of the weak targets that appear in submitted travel plans: "encourage sustainable travel", "promote cycling", "reduce reliance on the private car". None of those can be checked in three years, so none of them can be enforced, and a planning officer who is paying attention will ask you to replace them before the document is approved. Setting travel plan targets and a survey methodology that actually holds up means fixing the baseline, the mode, the number and the date at the same time.
The document itself sits near the bottom of the transport evidence hierarchy. A Travel Plan is usually secured by condition or by a section 106 obligation, often with a monitoring fee and sometimes with a bond. That matters for how you write it. Anything you put in the plan becomes a commitment that a monitoring officer will read back to your client years after you have closed the job.
What makes a target measurable
A usable target has four parts: a mode or behaviour, a numerical value, a measurement method and a date. Drop any one of them and the obligation becomes unenforceable.
Compare these two:
| Weak target | Measurable target |
|---|---|
| Reduce single-occupancy car trips | Single-occupancy car driver mode share for commuting trips to fall to 45 per cent by year three, measured by the staff travel survey described in section 6 |
| Promote cycle use | Cycle mode share for commuting trips to reach 8 per cent by year five, measured by the same survey, with cycle parking occupancy counts as supporting evidence |
The second version tells the monitoring officer what to look for and tells your client what they have signed up to. It also makes the target arguable at the application stage, which is the point at which you want the argument.
Avoid stacking targets. Four or five is normally enough for a residential scheme. A plan with fourteen targets across every mode looks thorough and is impossible to administer, so the whole document gets ignored.
Baseline surveys and when to run them
The baseline decides everything downstream, and on most schemes it does not exist yet, because the building has not been occupied. There are three honest routes.
For an existing site with an existing occupier, survey now, before the development changes anything. For a new build, you cannot survey the future occupants, so the baseline is either a census-derived travel-to-work profile for the relevant output area or ward, or a first-year survey carried out after occupation, with the targets expressed as changes from that first survey. For a relocation, survey the existing site and state plainly that the profile will shift because the new location has different accessibility.
The second route, a first-year baseline, is the one most authorities accept for new residential and commercial schemes. It has a trap. If the plan says the baseline survey happens within six months of first occupation and the scheme is phased over four years, you have measured a quarter-occupied building and set your targets against a profile that will not repeat. Say instead that the baseline survey takes place once a stated occupation threshold is reached, commonly 75 per cent, and that monitoring years are counted from that survey rather than from first occupation.
Timing within the year matters too. Run the survey in a neutral month, which in practice means avoiding August, late December and the school holidays, because term-time travel patterns are what the plan is about. A survey of a school-run catchment taken in half term is worthless.
Mode share targets against trip reduction targets
These two measure different things and fail in different ways.
A mode share target is expressed as a percentage of trips by each mode. It is self-normalising: if occupancy rises, the denominator rises with it, so the target stays meaningful. It is also the form most local authorities ask for, because it connects directly to the sustainable transport policies in the development plan and the NPPF (August 2026 edition).
A trip reduction target is expressed as an absolute number of vehicle trips in a stated period, usually the weekday peak hours. It is the right form where the highway authority's concern is junction capacity rather than travel behaviour, and where the Transport Assessment modelled a specific trip budget. The risk is that an absolute cap on vehicle trips becomes a cap on occupancy, which is not what anyone intended, so define the period, the direction and the counting method precisely.
On most schemes a mode share target is the primary measure and one absolute vehicle trip figure sits alongside it as a cross-check against the trip rates used in the transport evidence base. Where the Transport Assessment used TRICS trip rates, say which land use categories and which survey days were selected, because the monitoring surveys later get compared against them.
Survey method, sample size and response rates
A travel survey is only evidence if the response rate is high enough that the result is not an artefact of who bothered to reply. The plan should state the method, the population, the target response rate and what happens if it is missed.
- Define the survey population: all staff, all households, all pupils, or a stated subset such as full-time staff on site more than three days a week.
- State the instrument: an online questionnaire, a paper form issued with a reply envelope, or a face-to-face intercept survey at the entrance.
- Set a minimum response rate. For workplaces, 50 per cent of the survey population is a defensible floor and 30 per cent is the point at which most authorities start to doubt the result. For residential schemes, response rates are lower, so a stated minimum of 30 per cent with a non-response follow-up is more realistic.
- Record the travel-to-work or travel-to-site mode for a specified reference week, not a typical week, because "typical" invites recall error.
- Report the raw numbers alongside the percentages, so the reader can see the sample size behind each figure.
Add the supporting counts. Cycle parking occupancy, car park occupancy and, where relevant, an entry and exit vehicle count on a weekday give you physical evidence that does not depend on anyone filling in a form. They also catch the case where the questionnaire says cycle mode share has doubled and the cycle store is still half empty.
A worked illustration, clearly illustrative: a 120-staff office records a baseline survey with 68 responses, a 57 per cent response rate, of which 41 respondents drive alone. The reported single-occupancy car share is 60 per cent of respondents. If the year-three survey returns only 29 responses, that is a 24 per cent response rate and the comparison is not reliable. The plan should already say what happens next, which is normally a repeat survey within a stated window rather than a declared pass or fail.
Monitoring intervals and the reporting format
Five years from the baseline is the common monitoring period for residential and commercial schemes, with surveys in years one, three and five. Longer periods appear on large phased sites, sometimes tied to phase completion rather than calendar years.
The plan should name the deliverable: a monitoring report submitted to the local planning authority within a stated number of weeks of each survey, containing the raw survey data, the response rate, the comparison against each target, a note on measures delivered and a statement of whether remedial action is triggered. Give the report a named owner. A travel plan coordinator with a defined role is worth more than a named individual, because individuals leave.
Where a monitoring fee is secured through the section 106 agreement, the obligation usually funds the authority's own review of your report rather than the survey itself. Budget both.
Remedial measures when a target is missed
A travel plan that does not say what happens on failure is incomplete, and that is the gap most monitoring officers pick up on first.
The workable structure is a tiered action fund or a menu of additional measures, triggered when a target is missed by a stated margin. The menu has to be made up of things that are within the occupier's control and that cost money: additional cycle parking, a secured cycle store upgrade, a car club bay, a subsidised bus season ticket offer, a car share matching scheme with priority bays, a personalised travel planning exercise for new occupiers. Each entry should carry an indicative cost and a delivery timescale.
Resist open-ended wording. "The travel plan coordinator will consider further measures" commits nobody. "Where a target is missed by more than five percentage points, two measures from the list in Table 4 will be implemented within six months and reported in the following monitoring report" is a commitment that can be discharged, which is better for your client than a vague obligation hanging over the site.
Keeping the plan proportionate
The level of detail should match the scheme. A ten-dwelling scheme does not need a 40-page plan with a monitoring fund; a framework travel plan with two targets, one survey and a named coordinator is proportionate, and the PPG on travel plans supports that proportionality. A 300-unit scheme or a large employment site needs the full apparatus, because the trip numbers justify it.
Ask the highway authority at pre-application what form they want and whether they have a standard template or a published monitoring fee scale. Many do, and matching their format removes a round of comments. Check whether the authority expects the plan to be secured by condition or by obligation, because that changes who enforces it and how.
Where a Travel Plan sits alongside other transport documents, keep the trip figures consistent. A travel plan that quotes a different peak-hour vehicle figure from the Transport Assessment invites a consultee to query both. You can see how the Travel Plan relates to the rest of the submission pack in the full list of report types, and the same discipline applies to the monitoring assumptions in a sustainability calculation or the staged credit evidence in a BREEAM pre-assessment.
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 a reasonable travel plan monitoring period?
Five years from the baseline survey is the usual period for residential and commercial schemes, with surveys in years one, three and five. Large phased sites sometimes tie monitoring to phase completion instead of calendar years. Check what the highway authority expects at pre-application, because many publish a standard monitoring period and fee scale alongside their travel plan guidance.
Can a travel plan baseline be taken from census data?
Yes, for a new build where there are no occupants to survey. A travel-to-work profile for the relevant output area or ward gives a defensible starting point. Most authorities prefer a first-year survey once a stated occupation threshold is reached, commonly 75 per cent, with targets expressed as changes from that survey rather than from the census figures.
What response rate does a travel survey need?
For workplaces, 50 per cent of the defined survey population is a defensible floor and anything below about 30 per cent invites doubt. Residential schemes return lower rates, so a stated minimum of 30 per cent with a non-response follow-up is more realistic. State the minimum in the plan and say what happens if the survey misses it.
Is a travel plan secured by condition or by section 106?
Both routes are used. A condition requiring submission and approval of a travel plan is common on smaller schemes. Larger schemes are usually secured by a section 106 obligation, often with a monitoring fee and sometimes an action fund. The route affects who enforces the plan, so confirm it with the authority before drafting.
What should happen when a travel plan target is missed?
The plan should set out a tiered menu of additional measures with indicative costs and delivery timescales, triggered when a target is missed by a stated margin. Examples include extra cycle parking, a car club bay, subsidised bus tickets or personalised travel planning. Avoid wording that only commits the coordinator to consider further action.
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.