Page under development: last updated 2 March 2003

New Roundabout at Fermi Avenue/ A4185 Junction

Description

The new roundabout is being built slightly to the west of the A4185. When it is completed, the road will be slightly realigned to meet it at the northern and southern arms of the roundabout. The roundabout will link to Fermi Avenue by a short stretch of dual-carriageway to the existing roundabout at the eastern end of Fermi Avenue. Note the two-lane approaches to the roundabout on all arms; and in particular the unrestricted left-turn for traffic heading into Fermi Avenue from the south. So, traffic coming from the north and turning right into Fermi Avenue will join the right-hand lane of the dual carriageway section, while traffic coming from the south and turning left will go directly into the left-hand lane, without having to give way at the roundabout.

A short cycle bypass lane, using the old course of the A4185, will permit cyclists heading south towards Chilton to avoid the roundabout completely, though they will need to give way when rejoining the traffic south of the roundabout. There will also be some short shared-use paths leading from the western side of the northern arm of the roundabout which, after several road crossings, will join the existing segregated Fermi Avenue cycle path. Cyclists from the south heading into Fermi Avenue will be able to use a new connection to the existing Fermi Avenue cycle path, avoiding the roundabout.

Problems

We consider there to be three main problems:

Cyclists heading for Fermi Avenue from the north have little choice but to turn right at the roundabout, and so will emerge into the right-hand lane of the link road with fast traffic coming in from the left.
Cyclists heading northbound along the A4185 from Chilton will have to pull into the right-hand approach lane to join the roundabout, at a location where the road layout encourages any left-turning vehicles behind to travel at speed.
The width of the circulating carriageway and large turning radii will encourage high entry and exit speeds on the roundabout, which will generally increase the risk for cyclists.

[For more information on problems for cyclists at roundabouts, and what can be done about them, see DfT Traffic Advisory Leaflet 9/97 Cyclists at Roundabouts]

Some further points to note:

The national speed limit applies on the A4185. There are plans, supported by UKAEA, for a reduced (40 mph) speed limit along the A4185 as far as the Winnaway to improve safety at all site entrances and crossing points. This would be accompanied by pedestrian refuges at the Winnaway and Ickneild Way. However, little progress has been made in implementing these plans so the new roundabout will operate at national speed limit for some time to come.
A HarBUG survey in 2000 found that Fermi Avenue was the entrance used by aroudn 40% of cyclists.
The survey data suggest that there are likely to be 20 to 40 cyclists each day turning into Fermi Avenue, depending on time of year. Recent work by Sustrans, supported by UKAEA and the County, to improve cycle routes between Didcot and Wantage, is likely to increase this number.
The majority of cyclists heading for Fermi Avenue will be travelling from the north and, given the lack of suitable alternative routes, will want to turn right at the new roundabout.
By bringing right-turning cyclists into the right-hand lane of the dual carriageway link, the road layout will make it even harder to get onto the existing segregated cycle path on Fermi Avenue.

Who is responsible

Although the scheme is being managed by UKAEA as part of the Diamond development, it is still part of the public highway so Oxfordshire County Council has full responsibility for approving the design. Oxfordshire County Council has quite clear policies on the need for ensuring that cyclists are provided for in new developer and highway schemes, for example its Cycling Strategy states:

"It is important to assess all proposed highway and traffic management schemes to ensure firstly that they do not make conditions worse for cyclists and, secondly, that full advantage is taken in the design of such schemes of opportunities to improve cycling conditions.."

[For more information on Oxfordshire's policies on cycling see Oxfordshire's Local Transport Plan and Cycling Strategy]

Oxfordshire also has made a policy committment to introduce Vulnerable Road User Audit Procedures: " [CS15] ...to be applied to all highway and traffic management schemes (including developer-led schemes). The procedures will aim to ensure that the planning and design of schemes maximises the potential benefits and minimises the potential disbenefits, as far as is practicable, in terms of the coherence, directness, safety, attractive-ness and comfort of travel by pedestrians, cyclists and people with mobility or sensory difficulties."

[Vulnerable Road User Audit is based on the IHT/ DfT Cycle Audit and Cycle Review methodology. For more information see DfT Traffic Advisory Leaflet 7/98 Cycle Audit and Review]

Harwell Bicycle Users Group considers that county policy has not been followed in the design of this scheme, and calls for this situation to be remedied urgently.

Some specific suggestions:

The unrestricted left-turn should be removed, with the priorities changed so that all vehicles have to give way at the roundabout.
Work on the planned A4185 pedestrian crossings and reduced speed limit needs to be progressed and coordinated with the new roundabout, so that it is built for a design speed appropriate for the location.
The geometry of the roundabout needs to be 'tightened', with reduced turning radii and lane widths so that entry and exit speeds are reduced. (This was done for a new roundabout on the Didcot link road, so it can be done!).

We will update this page as our campaign progresses. In the meantime, please write to the County Council as soon as possible and raise it with your employer as a site safety issue.

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