Issue - meetings

Report ES19033

Approval was sought to construct a raised table at the mini-roundabout junction of Loop Road and Ashfield Lane, Chislehurst in response to a number of collisions at the junction and their pattern. The mini-roundabout has been a particular safety concern for many years; the carriageways of Ashfield Lane and Loop Road at their intersection in the middle of Chislehurst common are narrow, carrying a reasonably high volume of traffic, including buses. Vehicles are often seen over-running corners or being driven close to the edge of the carriageway.

The mini-roundabout was originally implemented to reduce collisions and speed at the junction but personal injury collisions have continued even though further alterations have been made e.g. realignment to the kerbs for increased deflection and buff surfacing on approaches.

The general arrangement for the proposed table was outlined in draft drawing 12893-01 Rev B appended to Report ES19033. Although the Council has a preference for non-vertical schemes to reduce speed, following past implementation of a number of schemes and with no viable new alternative apparent to reduce injury collisions at the junction, consistent with policy one was proposed in this instance. A raised table would slow vehicles at the mini-roundabout and afford drivers increased time to assess whether a manoeuvre is safe. A “virtual” speed table (coloured road surface through the junction) was considered but assessed as less likely to sufficiently improve driver behaviour. Changing priorities at the junction to give way lines on Ashfield Lane was also considered as was a priority give way feature on the Eastern arm (or both arms) of Ashfield Lane to reduce traffic speeds approaching the junction. Closing a section of Ashfield Lane was additionally considered. However, the proposals would create additional congestion on the common, particularly during busy times of day.

Bollards will be required to deter vehicles from over running the footway given a very low upstand between the kerb and carriageway from a raised table. With the bollards needing to be 450mm from the kerb edge, the footways will need widening slightly at the junctions to allow pedestrian access, particularly pedestrians with mobility issues and push chairs. Initial approval has been received from the Trustees of Chislehurst Common to use small amounts of Common Land for the footway widening. Before the scheme is implemented, the detailed design will need to be approved by the Trustees.

The proposal is estimated to cost £60k funded from the £574k allocation for casualty reduction and road danger reduction in the 2019/20 LIP budget agreed by TfL. Future maintenance costs would be contained within existing highway maintenance budgets.

Cllr Kieran Terry (Chislehurst Ward) provided a short PowerPoint presentation supporting the proposed scheme. Details are at Appendix C. The Assistant Director, Traffic and Parking, indicated that no other cost effective solutions can be provided - cost benefit being taken into account. Supporting the proposed solution, including slightly extending the roundabout into the junction road arms, a Member indicated that drivers can be in the position of not  ...  view the full minutes text for item 8