Purpose of a Transport Assessment (TA), Transport Statement (TS)
A TA is more comprehensive that a TS. The key difference between a TS and a TA is that a TA will assess and demonstrate the traffic and transport impact of a development over a wider area, beyond simply the site access and the site itself. In most cases, the council will require the detailed scope of a TA to be agreed at the pre-application stage.
A TA will be expected to demonstrate how a development sits against paragraph 115 of National Planning Policy Framework (NPPF) and give the Local Highway Authority (LHA) sufficient information to consider whether the development should be advised for approval given the tests for advising refusal set out in paragraph 116 of NPPF.
Expectations from a Transport Assessment
National Planning Policy Framework (NPPF) defines a Transport Assessment (TA) as, “A comprehensive and systematic process that considers and sets out transport issues relating to a proposed development, in the context of the vision for the scheme. It identifies measures required to support alternatives to the car such as walking, cycling and public transport, and to promote accessibility and safety, together with measures that will be needed deal with the anticipated transport impacts of the development.”
The LHA will typically expect a TA to demonstrate the following aspects of the development. The list below is not exhaustive; neither will each matter need to be considered for every development. Please refer to the Planning Policy Guidance (PPG) and Guidance on Transport Assessment (GTA) for more information.
- Full description of development, including land use, scale, phasing, number of employees if non-residential, how it is expected to operate (e.g. hours, shifts), and in the case of non-residential development whether it is speculative or if a specific operator is identified.
- Demonstrate that the proposed level of parking is in accordance with the LHA’s minimum parking standards (see Highway layouts and design) or otherwise acceptable. For some developments, a parking strategy, including monitoring or parking on and off-site, may be required.
- Demonstrate that servicing provision is suitable (including vehicle swept path analysis) such that there would not be an unacceptable impact on the highway (such as by reversing onto or queuing on the highway).
- Site location and baseline transport and highway conditions. Depending on the location and scale of development, a detailed understanding should be demonstrated with respect to all modes of travel and other locational transport characteristics. This should include a detailed review of sustainable accessibility (see under ‘Sustainable Transport and Active Travel’).
- Propose and promote sustainable accessibility improvements to demonstrate compliance with the Leicestershire Highway Design Guide (LHDG) and the NPPF, December 2024. For some developments, a detailed sustainable access strategy will be required. Proposals could include pedestrian and / or cycle crossings, footway and cycleway improvements, bus infrastructure, bus service proposals and so on.
- Safe and suitable access for all users (see under ‘Safe and Suitable Access’). In all cases, as well as being safe and able to accommodate appropriate vehicles, the site access will be expected to demonstrate that it can operate within normally accepted thresholds of practical capacity.
- Full details of predicted multi-modal trip generation and breakdown. Details / methodology to be agreed pre-application in most cases. If TRICS is used, whilst 85th percentile rates should be used where these can be justified, in most cases the LHA will accept average trip rates.
- Details of any vehicle trip breakdown (such as for retail developments).
- Any trip netting due to existing or permitted land uses on the site which would be replaced, must be agreed at the pre-application stage;
- Full details of vehicle trip distribution, and vehicle trip assignment. Details / methodology to be agreed pre-application in most cases. If a TA is required, the LHA strongly recommend Pan Regional Transport Model (PRTM) is used (to a varying degree depending on scale and location of development);
- Traffic flow scenarios. The TA should develop network / development specific (to be agreed via scoping) peak hour flow assessment traffic flows as follows:
- Base year
- Future assessment year of Planning Application plus five years as a minimum, with and without development;
- Depending on the scale and nature of development and the assessment, other assessment years may be required, for example correspondence with development phases if relevant / appropriate, local plan years, PRTM model years;
- All future assessment year scenarios are required to include all committed and Local Plan development flows as well as take account of any improvements on the network. The use of PRTM is strongly recommended in this respect to provide a bespoke growth rate/s, even if the nature of development would not strongly recommend PRTM is used (to a varying degree depending on scale and location of development). Also see “Preparing Development Proposals”.
- Off-site detailed junction modelling to establish development-related traffic impact. Depending on the nature and location of an off-site junction, the LHA may require the scope of assessment to include any junction that experiences a development-related change of 30 or more two-way vehicle trips to be modelled in detail. Junctions subject to existing congestion may be required to be modelled for lower number of trips, as may junctions where other issues could exist. The scope of assessment may be required to match an ‘Area of Influence’ identified via PRTM.
- Mitigation proposals for significant impacts on junction operation (see under ‘Mitigating impact on road safety or the network’). As with site access proposals, any physical mitigation proposals or other improvements on the highway network are required to be supported by a satisfactory Stage 1 Road Safety Audit, Designer’s Response and an amended design if required. Mitigation proposals are required to be deliverable within adopted highway and / or land under the control of the Applicant. It may be appropriate for a phased mitigation strategy to be developed in line with proposed development build-out phases, otherwise full mitigation is likely to be require prior to first occupation / opening.
- Personal Injury Collision (PIC) data is required to be reviewed for the most-recent five-year period for which data is available on the highway network within either 500m of the site access in each direction or over the scope of network considered for traffic impact, whichever is greater. The analysis should identify any patterns of PICS which could be exacerbated by proposed development trips and, if so, set out appropriate mitigation or remedial road safety measures.
- Highway impact of site construction works, including details of any abnormal loads and how any demolition would be undertaken.
A TA must demonstrate that a development is clearly acceptable against the tests for refusal set out in NPPF paragraph 116, to the LHA’s satisfaction.