Saturday, March 24, 2012

Perne Road roundabout: room for improvements

A county council consultation on a proposed “continental” redesign of the Perne Road/ Radegund Road roundabout has just closed. The current layout of this roundabout allows vehicles to use the fastest and most direct line through the roundabout, which means that speeds are high and it can be hostile for cyclists and pedestrians. This roundabout lies on a main cycle route that is used by both commuters and school children crossing from Birdwood Road to Radegund Road and it is a known accident site for cyclists.

The proposed new layout (see below) significantly reduces the space for traffic around the roundabout and tightens both the exits and entries into the roundabout. The design follows guidance from the Department for Transport on making roundabouts more cycle-friendly. The change in geometry will ensure that drivers keep their speeds low, and this should improve safety for both pedestrians and cyclists, particularly for on-road cyclists.


The proposed design has a good safety record in Europe, where it is usually combined with a peripheral cycle path around the outside of the roundabout. But there are some complicating factors here: this location has relatively high levels of traffic and the proposed design does not include any off-road cycle paths. There are good reasons for excluding the off-road cycle paths from the design: firstly, all of the existing cycle routes are on-road cycle lanes; and secondly adding any off-road paths would significantly increase the construction costs.

We met with the cycling officers on 16 March to discuss the proposed design and our CTC response to the consultation. We broadly welcome the new design because the core design objective of reducing the vehicle speeds should make this a safer junction for pedestrians and cyclists. But neither CTC, nor Cambridge Cycling Campaign are confident that the proposed design is the best option. CTC asked for two “modest” changes to the design: firstly to modify the new build outs so that cyclists can ride over these build outs to bypass stationary traffic at peak times (we think there is a risk of new “pinch points” at the entry and exits of the roundabout). Secondly, to include “desire-line” pedestrian and cycle crossing points on both Perne Road arms (currently, crossings are only proposed for the Birdwood Road and Radegund Road arms).

During the meeting we were shown some alternative designs that had been considered and rejected, including some designs with various off-road cycle path elements. These off-road options have some attractive elements, but there are also some reservations with any of the off-road alternatives. For example, the transition from the on-road cycle lane onto a peripheral off-road cycle path would introduce inconvenient sharp bends at the entry and exit points. Also, a peripheral cycle path would require two separate cycle crossing points on the Perne Road arms. As a result, we prefer the on-road option (keeping cyclists on the main carriageway). This preference is in line with general CTC policy, and the reduced vehicle speeds should make this option even safer.

The conclusion of the meeting was to look again the proposed design, both to look at some possible improvements and also to consider a possible temporary trial of the design (where part of the design is implemented with concrete blocks rather than by permanent construction). We see benefits if this trial can be achieved at low cost: this will allow the key elements of the design to be tested with real traffic to find out if it works as expected (and what doesn’t work!). We intend to stay involved in this project and to continue to work with the council to search for a good design. Hopefully, the lessons learned from this trial can then be applied to other roundabouts in Cambridge.

Wednesday, March 14, 2012

"Your Community - Your Speed Limit"

The County Council's new "Your Community - Your Speed Limit" policy enables Parish Councils to change the speed limits provided that they are prepared to fund them. Parish councils are now using this new policy to submit Proposed Traffic Regulation Orders (TROs) that propose reduced speed limits.

Barton Parish Council has submitted a set of TRO proposals:
  1. Implement a 40 mph speed limit on the length of New Road (B1046) that is currently national speed limit.
  2. Implement a 40 mph speed limit on Cambridge Road from a point 277 metres north east of its junction with New Road to a point 945 metres south west of this junction.
  3. Implement a 30mph speed limit through the village where there is currently a 40 mph speed limit.
  4. Implement a 50 mph speed limit on Wimpole Road from a point 274 metres west of its junction with Haslingfield Road in a westerly direction for a distance of 800 metres.
Great & Little Eversden Parish Council has submitted one TRO proposal:
  1. Reduce the speed limit to 30 mph on the main roads through the two villages which are currently subject to a 40 mph speed limit.
We strongly support these proposed reductions in speed limits. There is a large body of evidence that shows that speed reduction is the single most effective method to reduce deaths and injuries to cyclists and pedestrians. It also makes the village environment more pleasant.

You can help. Why not contact your local parish councillors and encourage more of our local parish councils to take advantage of this "Your Community - Your Speed Limit" policy.

Sunday, March 11, 2012

Those tiny busway posts – proposed solution in sight

The busway team have agreed to add some markings to make those annoying short steel posts in the busway more visible for cyclists. The proposed solution is a surface marking of tapered white lines on both sides of the post combined with a red-led “cateye” at the point of each taper. The basic marking (without the light) is shown below.

Saturday, March 10, 2012

Northstowe: New plans for Phase 1

The developers have dusted off their drawing boards and submitted a new set of plans for the first phase of the Northstowe development. This is a development we intend to follow closely and campaign for excellent cycling infrastructure. We hope it will capture the full cycling spirit of Cambridge and be a role model for good cycling development. But first impressions are disappointing: these first plans propose 3m wide shared-use cycle paths (which is the minimum recommended width in LTN 02/08) and appear to have dropped one of the previously planned cycle routes. So if you are in the area, why not turn up to one of the public consultations and ask some detailed questions about the cycling facilities that are planned.