The facts
Client:
Bridgend County Borough Council
Location: South Wales
Services: Highway Design
Sector: Transport
Start/Completion: 2009
The project
Junction 36 of the M4 motorway in South Wales is a
dumbbell junction which has experienced congestion problems for an
extended peak period, a problem which was exacerbated by the out of
town shopping centre accessed directly from the
junction.
On behalf of Bridgend County Borough Council, ways of
alleviating the problems at this location were studied in a two
stage process:
- Stage 1: Analysis of the existing situation and proposals for
short term improvements;
- Stage 2: Long term improvements to the junction.
Via video surveys the first comprehensive
survey of the junction was undertaken to provide a clear picture of
the interaction of movements through the dumbbell design.
The short term recommendations was for partial
closure of the circulatory combined with signalisation and a
hamburger arrangement at the southern roundabout. This was
predicted to provide a minimum 25% increase in capacity. These
proposals have since been implemented and shown to work very
successfully.
In the long term a second bridge across the M4
is proposed to remove traffic from Junction 36 and permit
further development in the area to be undertaken.