What is a Transport Assessment?

The National Planning Policy Framework states that all developments that generate significant amounts of movement should be supported by a Transport Statement or Transport Assessment and submitted with a planning application for the development. It will then be used to determine whether the transport impact of the development is acceptable.

Transport Assessments are normally produced by specialist transport planning professionals such as Sanderson Associates on behalf of developers and are used by decision makers in the planning process.

A Transport Assessment is a comprehensive and systematic process that sets out transport issues relating to a proposed development. It identifies what measures will be taken to deal with the anticipated transport impacts of the scheme and to improve accessibility and safety for all modes of travel, particularly for alternatives to the car such as walking, cycling and public transport.

In some cases, the transport issues arising out of a development proposal may not require a full Transport Assessment to inform the process adequately and identify suitable mitigation. In these instances, it has become common practice to produce a simplified report in the form of a Transport Statement. There will also be situations where the transport issues relating to a development proposal are limited, and no formal assessment is necessary.

Transport Assessments should consider the impact of the development on all transport modes, set out proposals to minimise the impact of the development on the transport network and promote measures to encourage sustainable transport. To this end, it is a usual requirement that a Transport Assessment is accompanied by a Travel Plan that will be implemented as part of the development proposals upon occupation and sets out measures to encourage sustainable transport.

The Transport Assessment process and the development of measures to encourage sustainable travel should be developed through consultation with the relevant authorities. This is an iterative process that often requires a number of revisions to the development proposals and sustainable travel measures before it can be agreed that the transport impact of the development has been reduced to a minimum. At this point the residual transport impact is assessed and mitigation measures are designed as necessary. The diagram below outlines the normal approach:-

Recommended Approach to a Transport Assessment

This iterative approach to the Transport Assessment ensures that improvements to sustainable modes of transport are always considered first, with measures to increase the capacity of roads or junctions only considered at the end of the process to mitigate the residual traffic impact of the development.

Transport Assessments identify the impact of the development in ‘person trips’, which are then broken down by transport mode. This normally involves the use of the nationally accepted TRICS database that enables the calculation of person/vehicle trips rates for different forms of development. Alternatively the use of bespoke survey data from other development sites are used, which can give a more accurate estimate of trip generation if a suitably representative site can be found in close proximity to the development site being considered.

Once development trips have been estimated, the distribution of trips can be predicted though various techniques, including gravity models or using existing travel pattern information or other empirical data. Information is also gathered on any existing person/vehicle trips from the existing use of the site and these are discounted from the network, to produce a net increase or decrease in trips within agreed assessment periods, which are usually considered during weekday AM/PM and weekend peak hour periods.

Once the net trip predictions are known, the local transport network is examined to establish whether capacity exists that can adequately accommodate development trips. When assessing the traffic impact on the highway network, this usually requires assessment of the immediate highway links and junction connections, with the scope of assessment limited to the highway network where the potential for material impact is anticipated. The traffic assessment will potentially include junction modelling of traffic movements in existing, opening and future design year scenarios, which are normally at least 5 years hence. Surveys of existing traffic flows on the local network are required to establish the base situation, with traffic growth factors applied to predict future design year conditions, derived through the National Trip End Model (NTEM) forecasts or other empirical data.

Based on traffic surveys undertaken by Sanderson Associates at various locations throughout the United Kingdom between 2005 and 2011, it is clear that traffic volumes have not increased to the extent previously estimated. In some cases base traffic levels have decreased by up to 10% over this time period, resulting in improvements in network performance rather than capacity problems that were previously forecast. These changes in traffic growth forecasts have now been recognised by the Department for Transport and can be calculated using TEMPro software.

Where the traffic assessment identifies that the level of additional traffic movements cannot be accommodated by existing infrastructure, then off site highway improvements need to be considered to ensure that the impact of the development is neutral, i.e. that it is no worse than existing circumstances. Similarly pedestrian/cycle routes and public transport facilities are examined and if improvements are necessary to accommodate development trips, then improvements need to be considered to these facilities to encourage access by sustainable modes.

The operational safety of a development is a key consideration and a detailed appraisal of the recorded personal injury accident records for the local highway network is usually required, determining casualty, linked factors and common problems that may need to be addressed as part of the development.

The assessment concludes with a summary of its findings and recommendations outlining the developments compliance with National Planning Policy Framework (NPPF 2012) and Local Plans.

Local Plans are produced by each local planning authority and is the key to delivering sustainable development that reflects the vision and aspirations of the local community. Planning decisions must be taken in accordance with the plan unless material considerations indicate otherwise.

Local Plans are designed to contribute to the achievement of sustainable development. To this end, they should be consistent with the principles and policies set out in National Planning Policy Framework, including presumption in favour of development.

Require Assistance with a Transport Assessment?

Sanderson Associates have extensive experience in providing Transport Assessments, Transport Statements and Travel Plans for a wide variety of major and minor developments throughout the whole of the UK, Isle of Man and Ireland.

We would be pleased to provide you with our competitive fee proposal to provide you with our Transport Assessment Services, please call us on 01924 844080 or click here to complete our secure online form.


What our Clients' say:

Advice on Site Drainage

Wed 22 June 2016

We consulted Sanderson Associates with regard to a surface water drainage design issue that we had recently. They were prompt in their response to us and were able to cut right through to the heart of the problem and provide advice that was direct and uncomplicated. The information provided satisfied the requirements of the local […]

Highway Advice – Testimonial

Mon 9 May 2016

Bob came to the island as an, ‘expert witness’, in a Planning Appeal, for a sizeable property build, essentially covering the Highway issues. After meeting Bob the day before the Appeal, it was abundantly clear this chap, ‘knew his stuff’. His consummate professionalism, experience and knowledge came though at the Hearing, contributing to the process […]

Transport Report in Opposition to Proposed Large Scale Housing

Tue 5 April 2016

We commissioned a Transport Report from Sanderson’s in opposition to a proposed large scale housing development near us. Ian Ladbrooke provided professional expertise in identifying the transport issues and the flaws in the developer’s transport assessment. His input proved invaluable and ultimately the application was refused on transport grounds. The report was delivered on time […]

Swept Path Analysis, Proposed Extension to Industrial Development

Mon 7 December 2015

As an independent property developer I was asked for a swept path analysis to aid my planning application. I googled and found Sanderson Associates, never had I heard of them before. I have to say from the start they were extremely professional and very prompt. I asked for many amendments on my analysis at the […]

Residential Development and Agricultural Access

Wed 16 September 2015

In my work as a planning consultant, I have come across a number of intransigent highway officers. Engaging Sandersons has allowed me to overcome these problems and secure planning consent for some difficult sites. They offer efficient and professional service which I can thoroughly recommend. Adrian Rose, Rose Consulting

Swept Path Analysis – Residential Development

Wed 5 August 2015

 Many thanks for the final swept path analysis drawings. Can I also say that its been a pleasure, and we will definitely use your services again on future projects. Richard On behalf of C E Gilbert & Son Developments Ltd

Swept Path Analysis

Mon 27 July 2015

We are a small civil engineering consultancy mainly involved in the design of housing developments. We often require swept-path analysis in order to satisfy local councils that their vehicles will be able to access the development. We send our site plans to Darren at Sanderson Associates who always provides a fast, efficient and consistent service. […]

Planning Appeal Rebuttal, Proposed Residential Property

Mon 13 July 2015

 We initially engaged Sanderson’s to carry out a traffic survey to support a planning application. They were recommended by our architect and their quote was very reasonable compared with other survey companies that we approached. Unfortunately, the initial survey was sabotaged when the monitoring tubes were pulled up by an unknown third party. Sanderson’s recommended […]

Flood Risk Assessment, Residential Development

Mon 15 June 2015

Sanderson Associates has provided us with a very professional service, and has always responded extremely quickly and efficiently to our client’s requirements. Laura Elias, Assistant Planner, CBRE Ltd

CPD Seminar Highway Development Control and Flood Risk

Tue 31 March 2015

I would like to thank the Team at Sandersons for providing CPD Seminars on Highway Development Control and Flood Risk to our Chartered Surveyors. The content of each meeting was both relevant and informative and gave useful, practical guidance on each topic. It is clear that Sandersons have a wealth of knowledge and expertise in […]

Transport Assessment, Anticipated Transport Impacts, Transport Statement, Transport Network, Sustainable Transport, Travel Plan, National Planning Policy Framework, NPPFDepartment For Transport, Person Trips, TRICS, Gravity Models Local Transport Network, National Trip End Model, PPG13 Transport