Junction Capacity Assessments
Assessing the Impact of Development Traffic on the Highway Network
Where a proposed development is expected to generate additional traffic, Highway Authorities may require evidence that the surrounding highway network can continue to operate safely and efficiently.
DW Transportation prepares Junction Capacity Assessments to evaluate the performance of existing and proposed highway junctions, providing robust technical evidence to support planning applications and respond to Highway Authority requirements.
What is a Junction Capacity Assessment?
A Junction Capacity Assessment evaluates how a junction is expected to perform with existing traffic levels and any additional traffic generated by a proposed development.
The assessment considers whether a junction has sufficient capacity to accommodate future traffic demand and identifies any potential impacts on vehicle queues, delays or operational performance.
These assessments help planning authorities and Highway Authorities understand whether a development is likely to have an unacceptable impact on the local highway network.
When is a Junction Capacity Assessment Required?
A Junction Capacity Assessment may be required where:
A development is expected to generate significant additional vehicle trips.
The Highway Authority has identified potential capacity concerns.
Existing junctions experience congestion during peak periods.
A new access junction is proposed.
Planning applications require evidence that the surrounding highway network can accommodate development traffic.
The level of assessment depends on the size and nature of the proposed development and the requirements of the local Highway Authority.
Evidence-Based Assessment
Every development is different. We begin by understanding the scale of the proposed development, expected traffic generation and the surrounding highway network.
Where appropriate, we review existing traffic data, commission new traffic surveys and undertake recognised junction capacity assessments using industry-standard software.
Our reports clearly explain the assessment methodology, modelling assumptions and results in plain English, helping planning officers and Highway Authorities understand the findings without unnecessary technical jargon.
Our Experience
DW Transportation has experience supporting planning applications where junction capacity has formed an important part of the transport planning assessment.
Whether assessing existing priority junctions, roundabouts or signal-controlled junctions, our objective is to provide clear, proportionate evidence that supports informed planning decisions.
Where improvements are required, we work with the wider design team to identify practical solutions that maintain the safe and efficient operation of the highway network.
Why Choose DW Transportation?
We recognise that junction capacity assessments should support planning decisions rather than simply produce technical outputs.
Our practical approach combines recognised assessment techniques with clear reporting, enabling clients, planning consultants and Highway Authorities to understand the implications of development traffic and identify proportionate solutions where necessary.
Frequently Asked Questions
What is a Junction Capacity Assessment?
A Junction Capacity Assessment evaluates how a highway junction performs with existing traffic and any additional traffic generated by a proposed development.
When is a Junction Capacity Assessment needed?
Highway Authorities may request one where a development could significantly affect the operation of nearby junctions or where there are existing concerns regarding traffic capacity.
What types of junction can be assessed?
Assessments can be undertaken for a range of junction types, including priority junctions, roundabouts and signal-controlled junctions, using recognised industry assessment techniques.
Does every planning application require a Junction Capacity Assessment?
No. They are generally required only where the scale or nature of a development justifies a more detailed assessment of highway network performance.
Need a Junction Capacity Assessment?
If your planning application requires a Junction Capacity Assessment or you have been asked to demonstrate the impact of development traffic on the surrounding highway network, DW Transportation can provide proportionate, evidence-based assessments tailored to your project.
We work with developers, architects and planning consultants throughout South Wales and across the UK.
Contact us today to discuss your project and find out how we can help.