Category Archives: Traffic Impact Assessment

“Default Yes” Housebuilding Near Train Stations

Unlocking Potential: Navigating “Default Yes” for Housing Near Stations

The UK government’s recent move toward a “Default Yes” approach for housebuilding near well-connected train stations marks a significant shift in planning policy. By streamlining the National Planning Policy Framework (NPPF), the aim is to accelerate the delivery of high-density, sustainable homes where they are needed most. However, building in such close proximity to active rail lines brings unique technical challenges that require expert navigation.

Managing Noise and Vibration

Developing sites adjacent to railway infrastructure necessitates rigorous environmental assessments. At the planning stage, a Noise Assessment is vital. We refer to ProPG: Planning & Noise, which provides a framework for managing noise in new residential developments. This is often coupled with internal sound insulation designs to meet BS 8233:2014 standards, ensuring residents enjoy a high-quality living environment despite the external hum of the network.

Equally critical is the Vibration Assessment. Railway traffic can cause ground-borne tremors that impact human comfort. We assess these risks in accordance with BS 6472-1:2008, which evaluates the “Vibration Dose Value” (VDV). Understanding these levels early allows for the integration of structural mitigation, such as anti-vibration mountings or specific foundation designs, preventing future complaints and ensuring structural integrity.

The Shift to Car-Free Development

Proximity to transport hubs is the primary driver for “car-free” or “permit-free” developments.

While these schemes reduce carbon footprints and maximise land use, local authorities often require proof that overspill parking won’t saturate neighbouring streets.

To support these applications, we conduct comprehensive Parking Surveys, typically following the “Lambeth Methodology“. These surveys involve “beat” counts during peak residential demand (usually between 00:30 and 05:30) to measure “parking stress” within a 200m walking distance of the site. Demonstrating that the local network can absorb any residual demand is often the final hurdle in securing planning permission.

Proven Expertise

With 15 years of experience in delivering noise and transport reports for complex, high-noise environments, we understand the nuances of railway-side development.

We have supported numerous medium-to-major projects, similar to the below:

  • Twickenham Station Redevelopment: A major mixed-use scheme integrating over 100 homes directly above and adjacent to a busy terminal.
  • Walthamstow Central: High-density residential blocks that leverage exceptional PTAL (Public Transport Accessibility Level) ratings.

Our team provides the technical evidence needed to satisfy both environmental health and highways officers. Given the fast-paced nature of “Default Yes” sites, we offer a short turnaround on all technical reporting to keep your project moving.

Case Studies

Noise Assessment 

Parking Survey 

Approximate Cost

For Noise, Vibration and Parking Surveys you can expect to pay.

Transport Assessment – Thurrock

Transport Assessment – Thurrock

Southwest Environmental Limited have recently been engaed to undertake a Transport Assessment for a School in Thurrock District Council

The Transport Assessment is to support a Planning Application for extension for a school. The extension includes numerous new class rooms as well as associated site layout improvements.

The transport assessment will include a baseline study, junction modelling and an assessment oif routes to and from the school.

SWEL have prepared numerous transport assessments in Thurrock, and can normally produce reports of this nature on a quick turn around.

We would be happy to discuss you project with you by phone or email. There is a no charge until we agree a fee for our services.

Traffic Impact Assessment – Essex

Traffic Impact Assessment – Grays, Essex

A waste recycling firm are applying for planning permission for a change of use. The change of use triggers the requrement for a traffic impact assessment.

First off the baseline conditions must be considered which involves a through traffic count on the surrounding road network.

Traffic Impact – Lots of Data

This data is then used to calculate likely percentage increases from the development.

The Traffic Impact assessment includes commentary on the modal split of traffic in the area and the trip generation associated with the proposed development.

Traffic Impact Assessment – Most counts are now automated.

When considering the different modes of transport it is important to consider that  a small number of HGVs are likely to represent a higher percentage increase, as opposed to a small number of cars the affect of which is diluted within the often high numbers of trips that are generated by cars on most roads on a day to day basis.

Traffic Impact Assessment