This post is part of this series on learnings from the Dutch CROW design manual for bicycle traffic.

Following on from last weeks post about designing roundabouts the Dutch way, I felt that before moving onto TCS junctions I should quickly cover larger standard roundabouts as there are a few unique items to point out.

Bi-directional Cycle Track

On large distributor roads or on through roads, where access to both sides of the road is not needed, crossing the road is difficult or impractical, it is recommended to have a bi-directional cycle track on one side of the road.

When it comes to meeting a large roundabout at a junction with another distributor or through road, the bi-directional track should simply be continued past the roundabout crossing one of the arms at a safe distance from the roundabout.

Bicycle Tunnel

On busy bicycle routes which cross a busy road, a tunnel can be used to increase safety and convenience of the bicycle route.

A tunnel should be used rather than a bridge since the tunnel will only have to do down the height of a cyclist (8 feet) whereas a bridge would have to go up their height of the tallest allowed vehicle (16 feet 6 inches). Also, with a tunnel, the bicycle rider can use momentum from the down slope into the tunnel to help climb the up slope out of it.