Can Existing Traffic Congestion Be Used to Refuse Planning Permission?
One of the most common concerns raised by developers is:
"The road is already busy. Does that mean my planning application will be refused?"
It's an understandable question, particularly where a site is located on an already congested road or close to a busy junction.
The simple answer is not necessarily.
Whilst existing traffic conditions are an important consideration, congestion on its own does not automatically prevent development from taking place. The planning system considers a range of factors before deciding whether the transport impacts of a development are acceptable.
This guide explains how traffic congestion is assessed during the planning process and what developers should expect.
Existing congestion does not automatically prevent development
Many successful developments are located on roads that already experience congestion during peak periods.
Town centres, retail parks, schools, employment areas and busy commuter routes often experience delays at certain times of the day. This does not mean that all future development must be refused.
Instead, the key question is whether the proposed development would create an unacceptable additional impact on the surrounding highway network.
What does the Highway Authority assess?
When reviewing a planning application, the Local Highway Authority will consider a range of transport matters rather than focusing solely on whether traffic queues already exist.
These typically include:
The amount of additional traffic generated by the development.
The safety of the proposed access.
The operation of nearby junctions.
Parking provision.
Opportunities for walking, cycling and public transport.
Servicing and delivery arrangements.
The cumulative impact of nearby developments.
The overall objective is to determine whether the development can be accommodated safely and whether any transport impacts are acceptable.
How is traffic impact assessed?
The level of assessment depends on the size and nature of the proposed development.
Smaller developments may only require a Transport Statement, while larger schemes are more likely to require a Transport Assessment supported by additional technical evidence.
Depending on the proposal, this may include:
Traffic surveys.
Trip generation assessments.
Junction capacity assessments.
Parking surveys.
Vehicle tracking.
Accessibility assessments.
The purpose is to provide objective evidence rather than relying on assumptions.
What if local residents object?
Traffic and congestion are common concerns raised by local residents during the planning process.
These comments are an important part of the consultation process and will be considered by the Local Planning Authority.
However, planning decisions are based on planning evidence rather than the number of objections received.
Where transport concerns are raised, the Local Highway Authority will normally provide technical advice to help inform the planning decision.
Can highway improvements overcome concerns?
Yes.
Where transport impacts are identified, it is often possible to reduce or mitigate those impacts through changes to the proposed development.
Examples include:
Improving the site access.
Providing additional parking.
Introducing pedestrian crossing facilities.
Altering the internal layout.
Improving visibility.
Upgrading nearby junctions.
Providing sustainable travel measures.
In some cases, these improvements may be delivered through a Section 278 Agreement with the Local Highway Authority.
Every development is different
There are no simple rules that determine whether congestion will prevent planning permission.
A small development may have very little impact on an already busy road, whilst a larger proposal may require detailed transport modelling to demonstrate that the surrounding highway network can continue to operate satisfactorily.
Every planning application is assessed on its own merits, taking account of the scale of development, the characteristics of the surrounding highway network and the evidence submitted in support of the application.
Why early transport planning advice matters
Transport issues are often much easier to resolve before a planning application is submitted than after concerns have been raised by the Local Highway Authority.
An experienced transport planning consultant can identify potential issues early, advise on the appropriate level of assessment and recommend practical solutions where necessary.
This can help reduce delays, avoid unnecessary redesign work and improve the overall quality of the planning application.
How DW Transportation can help
DW Transportation advises developers, architects and planning consultants on the transport implications of development proposals throughout South Wales and across the UK.
Whether you're concerned about existing traffic congestion, access arrangements, parking provision or Highway Authority comments, we provide clear, practical advice tailored to your development.
Our aim is to identify potential transport issues early and prepare proportionate evidence that supports a successful planning application.
Need advice?
If you're concerned that existing traffic congestion may affect your planning application, we'd be happy to discuss your proposals.
Early transport planning advice can often identify potential issues before an application is submitted and help determine the most appropriate strategy for addressing them.
Contact DW Transportation today for an informal discussion about your project.
About the Author
Dean Watkins is Director of DW Transportation, an independent transport planning consultancy based in South Wales. With over 25 years' experience in transport planning, Dean advises developers, architects and planning consultants on Transport Statements, Transport Assessments and highway matters associated with planning applications across South Wales and the UK.