1. Semi-turbo roundabout with right of way for cyclists
, Joost den Draaijer roundabout. In the summer of 2007 the first semi-turbo roundabout in the Hilversum (at least as far as we know) with right of way for cyclists was opened in Netherlands . In 2008 results of the evaluation are to be published. According to local authorities the first results are positive. Hilversum
2. Location and design
The semi-turbo opens up the town-centre side of Mediapark. Car intensities of the roundabout are approx. 20 to 25,000 mv/24h. In most cases a single-lane roundabout is possible at these intensities. The distribution of motor vehicles was, however, highly unequal over the various legs of the roundabout. Calculations made it clear that a single-lane roundabout would not suffice. Therefore a separate left-turn lane was installed from Sumatralaan to Mediapark.
3. Right of way for cyclists on two-lane entrance
This resulted in a semi-turbo roundabout. Two double-lane entrances have been used. All exits are single lane only. Cyclists have the right of way over motor vehicles entering or leaving the roundabout. As such, the roundabout meets the recommendations from CROW publication Eenheid in rotondes (publicatie 126), both in the number of lanes and in the right-of-way regime. Right of way for cyclists was self-evident for the local authorities. When taking the accompanying pictures some cyclists turned out to ride against traffic. These, too, could proceed without hindrance, as cars yielded.
4. Two lanes on entrance
At this two-lane entrance a small island has been used to separate the lanes. This anticipates the physical lane separation on the actual roundabout. The location, immediately in front of the cyclist and pedestrian crossings, raises awareness in drivers. From this point on they have to take into consideration the traffic on the roundabout: including cyclists and pedestrians. Moreover the crossing is subdivided for cyclists and pedestrians, allowing them to exercise their right of way more readily. A possible disadvantage of extra islands may be that it becomes less clear for crossing cyclists and pedestrians from which direction to expect traffic. According to elementary expectations, traffic comes from one direction on one side of an island, and from the opposite direction on the other side.
5. Physical lane separation
As is proper in a turbo roundabout, lanes on the roundabout are physically separated by a small ridge. This carries several advantages. Since drivers cannot change lanes on the roundabout, their workload is less. This decreases the chances of overlooking a cyclist or pedestrian on the exit. Another advantage of physical lane separation is the fact that drivers cannot cut corners. It is easier to realise the envisioned moderate speed.
6. Another two-lane entrance
On a subsidiary entrance two lanes have been realised as well. This is at Naarderweg coming from the town centre. This allows approaching drivers to change in time to the lane they require on the turbo roundabout. However, the semi-turbo would perform as well at this location with a single lane.
In accordance with CROW recommendations all legs have been provided with pedestrian crossings. In order to draw additional attention to crossing cyclists and pedestrians markings have been used on a large red background. Give-way road markings have also been applied for traffic leaving the roundabout (although this is strictly speaking not necessary, as traffic leaving the roundabout is turning off and should therefore give free passage to cyclists and pedestrians going straight ahead). In the picture Lage Naarderweg in a northerly direction.
8. No signalling
Cyclists often do not bother signalling their intentions. When leaving the roundabout they should extend their right hand, but this is often ignored particularly on roundabouts with bike paths. This is highly annoying for motorists who want to exit the roundabout. They often break to yield when the cyclist proves to turn right anyway. For this reason the bicycle exit has been located at some distance in front of the point of conflict car-bicycle (in accordance with CROW recommendations). At an early stage the motorist sees where the cyclist is heading for.
9. Surmountable areas
On Joost den Draaijer roundabout remarkably large surmountable areas have been deployed in the curves. This is caused by the presence of a large ProRail storage facility for rails and switches nearby. Quite regularly excessively large lorries with switches and such have to pass the roundabout at night. The roundabout was therefore designed in close co-operation with ProRail. Most drivers do not use the surmountable areas to cut corners.
Next to Joost den Draaijer roundabout is the location of the striking building of
voor Beeld en Geluid (broadcast museum). Nederlands Museum