Tag:cycleway=asl

Schematic illustration of advanced stop line markings.

A cycleway advanced stop line (ASL), also known as a bike box or an advanced stop box, is a marked area for cyclists in front of the stop line for motor traffic. They are most commonly found at traffic-light controlled junctions and allow cyclists a head start when the traffic signal changes from red to green.

Usage

• Create a new a few metres back from the junction node, ideally level with the stop line at the front of the painted box.
• If it is not a one-way then a direction tag is needed. Use key direction=* for this. Values are forward or backward. Example: direction=forward

Example

Do not tag the junction node itself: this is misleading because then nobody can tell which direction of approach the ASL applies to.

Further Information

Rationale and status

• These cycle facilities are common sights in UK cities and places like Portland, Oregon, USA. Junctions using them should be tagged, since their presence may be informative for cycle routing.

• "Advanced Stop Line" is the British English term for these facilities. "Bike box" is also documented here, but Wikipedia prefers the former.

• Abbreviations are short and sometimes easy to remember.

Routing and data model

No fancy relation is necessary, which keeps things simple for mappers. ASL nodes are always connected to their junctions by the way they're on. Find the nearest highway junction node along the way it's on, and that gives you both the associated junction and the applicable direction.

Open issues

• Feeder (cycle) lane vs not?
  • If the feeder cycle lane goes for a significant distance along the road, then cycleway=lane will have been used. If it's a very short feeder cycle lane, you could cut the way and tag that short way with the lane, with the way being the length of the cycle lane.
• ASLs for other types of vehicle. Are there any?