A new roundabout design which includes large bicycle logos marked in the single lane of the roundabout is causing some confusing.
The design — which is based on the National Cycle Manual — has been implemented by Dun Laoghaire-Rathdown County Council on the Sandyford Hall roundabout on the Kilgobbin Road in south Dublin.
Herald.ie has a photograph of the roundabout, in an article covering the confusion. However, the article it self incorrectly and confusingly calls the main and only lane on the roundabout a “cycle lane” and “the lane marked for bicycles”.
The roundabout is a single-lane roundabout, the centre overrun area is exclusively for large buses and trucks.
Below is what the National Cycle Manual says about this type of roundabout… (It’s also worth looking at the section of the manual on roundabouts to read the design principles of cycling-friendly roundabouts and the general principles of the manual)
Shared Roundabouts are characterised by a built central island clearly defined by a solid kerb, minimum 150mm high, and with a radius of 2.0m or larger. An overrun can be provided to facilitate larger vehicles if required. Shared roundabouts have single traffic lane approaches and a shared single circulating lane no wider than 4.0m.
Shared roundabouts can be used in mixed street environments at junctions with design capacities of up to 6,000 vehicles per day, and where the vehicular speed on the approach roads is less than 50km/h.
- Cyclists mixed with traffic on single circulating lane
- Not suitable where high cycle numbers anticipated
- May be appropriate to consider plateaux on each approach to roundabout
- Safety assessment measured against local control data (safety record, local accident data)