Healthy Streets and transport assessment in London

In London, the transport question is not only how many vehicle trips a scheme generates. Policy T4 of the London Plan 2021 asks whether the development is integrated with current and planned transport capacity and connectivity, and whether it supports the Healthy Streets approach set out in Policy T2. A transport assessment that reports junction capacity and nothing else will be sent back.

The practical test for a major scheme: can you show that the people living or working there can reach what they need on foot, by bicycle or by public transport, and that the streets around the site get better rather than busier.

What the Healthy Streets approach asks of a scheme

Policy T2 requires development proposals to deliver improvements that support the Healthy Streets Indicators. There are ten of them, and they cover the experience of being on a street rather than its traffic performance: pedestrians from all walks of life, easy to cross, shade and shelter, places to stop and rest, not too noisy, people choosing to walk, cycle and use public transport, people feeling safe, things to see and do, people feeling relaxed, and clean air.

That framing changes what the evidence looks like. Crossing distances, footway widths, dropped kerbs, street trees, seating, lighting, active frontage and the absence of guard railing all become assessable matters, and they belong in the transport submission rather than only in the landscape drawings.

The Mayor's Transport Strategy target of 80 per cent of trips in London made on foot, by cycle or by public transport by 2041 sits behind all of this. A scheme that proposes generous car parking and a token cycle store is arguing against the strategy, and officers will say so.

When a transport assessment is needed in London

Policy T4 expects a transport assessment where a development may generate transport impacts, with the scope proportionate to the scale and location of the scheme. There is no single London threshold in the way there is a national rule of thumb, and boroughs set their own expectations in local validation lists.

Referral to the Mayor is governed by the Town and Country Planning (Mayor of London) Order 2008, and the residential trigger that matters most in practice is 150 or more houses or flats. Active Travel England is also a statutory consultee on major applications at and above 150 units, so a scheme at that scale faces three sets of transport comments: borough, Transport for London and Active Travel England.

Scope the assessment before you write it. Every borough has a preferred approach to trip generation, assessment years and the treatment of public transport capacity, and agreeing those inputs in a scoping note costs far less than rerunning the work.

The indicators and how they are evidenced

A Healthy Streets assessment is a structured appraisal rather than a narrative. Transport for London publishes a check and a scoring approach, and the useful discipline is to assess the existing street, then the street as proposed, and report the change for each indicator.

What that means in evidence terms:

• a walking and cycling audit of the routes between the site and the nearest stations, bus stops, schools, shops and open spaces, with photographs and measured footway widths
• crossing provision mapped against desire lines, with waiting times at signalised crossings where known
• severance and road danger noted, supported by recorded collision data for a defined study area and period
• the proposed street design response drawn, with footway widths, crossings, trees, seating and cycle parking shown
• a statement of what the scheme delivers beyond its boundary, and how it will be secured

The gap in most submissions is the last point. Indicators improve because somebody builds a crossing, widens a footway or plants trees, and that requires a highway agreement and funding. Identify the works early and carry them into the obligations discussion, and where the site sits inside a designated growth area the expectations are higher again, as Opportunity Areas and what a London allocation changes sets out.

Public transport capacity and crowding evidence

Public transport access level, usually written as PTAL, gives a starting measure of accessibility and drives parking standards and density expectations. It is a blunt instrument. A site can hold a high rating because of a bus route that is already at capacity in the morning peak.

So the assessment needs two things beyond the rating. First, line and service specific capacity evidence for the peak hour, covering the bus routes, the station entrances and the interchange the scheme will rely on. Second, an assessment of the additional demand the scheme generates on each of those, with the mode split assumption stated and justified.

Where crowding is already a problem, expect a contribution towards capacity or towards station access improvements. Where a station has no step free access, expect that to be raised against the inclusive access case for the development. Neither is a reason not to build, but both are reasons to have the numbers before the first meeting rather than after it.

The honest uncertainty is the mode split. Trip rates from survey databases are drawn from sites that may not match the location, the tenure or the parking provision proposed, so state the source, state the adjustment and show the sensitivity if the assumption is challenged.

Active travel provision and the street design response

Cycle parking is a minimum standard in London and a frequent reason for a holding objection. The provision has to be the right quantity, in the right place, with the right access, and the drawings have to show it rather than schedule it.

The design matters more than the count. A long stay store reached by carrying a bicycle down a flight of steps will not be used, nor will a store behind two self closing doors on a narrow corridor. Put long stay parking at ground level, on the route people take, with a level or ramped approach and a door wide enough for a cargo bicycle. Put short stay stands within easy reach of the entrances, visible and overlooked.

For walking, the moves are ordinary: continuous footways across side road junctions, tighter corner radii, crossings on the desire line, no guard railing, planting that does not block sight lines, and surfaces that drain. The Travel Plan then carries the behavioural measures, with targets, a monitoring survey programme and a named travel plan coordinator.

Where Transport for London becomes involved

Transport for London wears several hats, and conflating them causes confusion.

1. As highway authority for the Transport for London Road Network, where any direct access, works or alteration needs its agreement.
2. As a statutory consultee and as adviser to the Mayor on referable applications, commenting on strategic transport policy compliance.
3. As an operator, on bus service impacts, stop relocations, station capacity and step free access.
4. As a landowner and development partner on sites it controls, which is a different relationship again.

Identify which hats apply to your site at the outset. A scheme fronting a borough road, with no bus stop and below the referral threshold, may never need to speak to Transport for London at all. A scheme on a red route at 200 units needs it in the room from the start.

Scoping with the borough and the Mayor's team

The sequence that works is short and front loaded.

Start with a written scoping note: site description, proposed quantum, access arrangement, proposed trip generation method and source, assessment years, study area, the junctions and crossings to be assessed, the Healthy Streets assessment approach, and the parking and cycle provision proposed against standards. Send it to the borough's highways officer and, where relevant, to Transport for London, and ask for written agreement.

Then hold the pre-application meeting with the drawings rather than with the policy. Officers respond to a layout they can mark up. Bring the walking and cycling audit photographs; they change the conversation faster than a table of trip rates, and the capacity argument about the scheme's own form is better had alongside the density discussion covered in optimising site capacity under London Plan policy D3.

Finally, write the assessment to answer the scope you agreed, and put a short table at the front mapping each policy requirement to the section that deals with it. Officers consulting on a 200 page document need that table more than they need the executive summary.

Enter your postcode on PlanScope to see which reports a London scheme at 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. Councils usually expect a transport assessment to be prepared by a suitably qualified transport planner, and professional review is strongly advised. This article is general guidance rather than legal advice.