After residents raised concerns to us about this roundabout, we asked the council to investigate.

An informal stage 4 Safety Audit and observation of traffic conditions has been completed and below are the results.

"I am not sure of the actual reason for the Trevone Way junction being a roundabout but I would imagine that it was installed as a speed reducing feature possibly to enable the 30mph zone to be extended. Cambourne Drive is well within the 30mph zone and would not therefore require the same treatment.

The safety audit raised the following issues.

1. PROBLEM

Westbound motorists overrun the thermoplastic mini-roundabout central island which could lead to conflict with eastbound traffic approaching the give way markings.

COMMENT

The central island is due to be domed in the very near future to a maximum height of 75mm. A domed white circle marking will deter light vehicles from overrunning and improve conspicuity.

Westbound motorists will be more likely to actually negotiate the roundabout rather than not reducing speed and driving straight over the white spot. Motorists exiting Trevone Way will also have to go around the central island rather than 'cutting the corner'.


2. PROBLEM

The existing road markings on Burtree Lane, on each approach to the mini-roundabout, are in need of renewing.

COMMENT

All the thermoplastic road markings on Burtree Lane, including 'SLOW' markings, warning lines, splitter islands, give way lines and give way triangles will be renewed very shortly.

It is important that a mini-roundabout is conspicuous to approaching drivers at all times and the renewal of all road markings will maximise driver awareness and improve lane discipline.


3. PROBLEM

The mini-roundabout is situated over the crest of a convex hill and westbound motorists are at risk of failing to give way because the vertical carriageway alignment restricts forward visibility of the give way markings and central island.

COMMENT

Forward visibility on the out of town (westbound) approach to the roundabout is below the normal minimum requirement of 70m. This reduces the conspicuity of the roundabout. As the mini-roundabout is over a hill and the minimum forward visibility cannot be achieved, care must be taken to ensure that drivers are made aware of the imminent presence of the mini-roundabout, by good signing and road markings.

The existing signing/lining layout appears to be adequate. On all approaches the mini-roundabout signs are clearly visible and illuminated, in addition the mini-roundabout signs on Burtree Lane have a highly conspicuous yellow backing board. Illuminated roundabout ahead warning signs with 'REDUCE SPEED NOW' plates are also present and they are located at the recommended distance away from the junction. The road marking arrangement isn't complicated and although all the road markings are currently in a poor condition this will be addressed shortly.
Buff coloured anti-skid surfacing on the approach and hazard marker posts in the northern verge also increase awareness of the junction.

In summary, the current mini-roundabout arrangement at Trevone Way appears to be operating reasonably well. Whilst it is acknowledged that the geometry of Burtree Lane reduces forward visibility of the roundabout this is counter balanced by enhanced and conspicuous signage and lining, albeit that the lining is in need of a refresh. It is my view that motorists cannot fail to appreciate that they are approaching a mini-roundabout, with all the road safety messages, if they are paying due care and attention"