Designs considered – Clophill roundabout consultation
Consultation closed: Monday, 11 July 2022
Consultation opened: Monday, 16 May 2022
We have considered the following options to help reduce congestion and improve traffic flow:
Option 1a: Signalised roundabout – traffic lights are introduced.
Option 1b: Improved roundabout – alterations to the roundabout layout with two lanes in and out of the roundabout from each direction.
Option 2: Signalised crossroads – the roundabout is replaced with a traffic light junction.
Option 3: Hamburger junction – a hybrid of signalised crossroads and a roundabout that allows some movements around a gyratory.
We modelled each option to test which design would best meet the objectives.
In terms of impact on traffic, we considered how each design would address the congestion issues, offer flexibility to cope with future traffic patterns and also maintain the required U-turn (road users leaving The Green in Clophill heading south on the A6 can use the roundabout to head back north on the A6). We also considered the scale of the change and cost.
| Assessment | Do nothing | Signalised roundabout | Improved roundabout | Signalised crossroads | Hamburger junction |
|---|---|---|---|---|---|
| Impact on current traffic congestion | High delays in all directions | Some improvement but queues still expected | Improvement with fewer delays compared to signalised options | Significant queues still expected | Minimal queues expected |
| U-turn provision | Yes | Yes | Yes | Yes | Yes, but signage changes needed |
| Improved pedestrian and cycle access | No change | Yes | Yes | Yes | Yes |
| Amount of change to the current layouts | None | Moderate | Minor | Significant | Significant |
| Cost of scheme | Not applicable | High | Moderate – compared to other options | Very high | Very high |
Our preferred option for the roundabout is 1b. improved roundabout.
Although the hamburger junction model addresses the current congestion issues the best, the scale of the change and therefore cost is the highest. The improved roundabout (option 1b), also addresses the current congestion issues but at a lower cost and this makes it our preferred option.
In 2021, our traffic analysis showed that creating two ahead lanes on the entry and exit of each arm of the roundabout would see the approximate journey time savings:
- on the A6 south-north route, 4 minutes in the morning and 7 minutes in the evening
- on the A507 east-west route, 5 minutes in the morning and 4 minutes in the evening
Road users would spend less time stuck in traffic and the smoother flowing traffic should have significant air quality benefits. The plans would include improvements for pedestrians and cyclists which are highlighted later on.
The new M1 to A6 link road is due to be built soon and the A507 is a corridor expected to benefit from new development both of which have the potential to increase traffic in the future. The improved roundabout would help support this potential growth as it provides the extra capacity to handle possible increases in traffic and the flexibility to adapt to any changing traffic patterns.