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:

Technical Letter in Support of Residential Development

Thu 28 July 2016

Recently worked with Robert in order to turn round a planning application which was being recommended for refusal due to Highways objections at the eleventh hour. On this one we had to really think out of the box quickly to mitigate the concerns. Robert was instrumental in coming up with options and innovative ideas and […]

Stage 3 Road Safety Audit

Mon 25 July 2016

The service provided was professional direct to the point and alternatives were provided on discussion of the reports requirements, a user friendly service in every way to a legacy job with very little background information. Thank you Steven Johnston – Keepmoat Regeneration Ltd

Flood Risk Assessment, Proposed Residential Development.

Fri 8 July 2016

Thank you for your assistance on the Flood Risk assessment in relation to our works being carried out at the house. I would like to add that I only called yesterday seeking advice on a flood risk assessment not knowing what it entails and you have acted extremely quickly. You listened and gave valuable, honest […]

Highways Advice, Proposed Residential Development, Micklepage Paddock

Wed 29 June 2016

I would just like to reiterate my thanks, together with those of my clients, for all the work that you did in assisting to obtain planning permission for the above project. Highways had always indicated that being able to provide adequate sight lines onto the main road would be a major factor in determining this […]

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

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