Advanced Stop Lines

Advanced stop lines (ASLs) are a common intervention for cycling at signalised junctions in Britain. Indeed, with the exception of shared use footways, combined with toucan crossings, they are currently the only available intervention for cycling at these kinds of junctions. 

We feel that, while ASLs can offer some advantages, they are often applied on the basis that they are better than nothing, and at many junctions are merely tokenistic. Better designs, suitable for any user, are necessary at these kinds of junctions.

Advantages of ASLs

• Can allow cyclists in the ASL to progress through the junction on green, ahead of motor vehicles, with less conflict.
• Similarly, right turns can be made from an ASL, ahead of motor vehicles.

Disadvantages

• All of the above advantages are only available when the signals are red. When signals are green, ASLs provide no benefit at the junction whatsoever. ASLs only work on a part-time basis.
• Feeder lanes to ASLs - and ASLs themselves - may encourage people to position themselves in the blindspots of vehicles. 
• ASLs may encourage, or simply force, people into dangerous positions on the inside of vehicles which are about to turn left.
• Attempts to avoid this problem - and left-hook conflicts in the junction itself - involve central feeder lanes, but these can be intimidating, and still involve conflicts with motor vehicles which will need to move across this lane. 
• ASLs do not provide a sufficient level of comfort and attractiveness at busier junctions.
• ASLs can (often legally) be encroached upon by motorists, limiting their effectiveness.

Advanced Stop Lines can be found in the Netherlands. However, they are only used in fairly specific contexts. The CROW manual recommends that they are used in conjunction with limited motor traffic capacity, particularly when many motor vehicles will be turning right (the equivalent of our left turn). For instance, the example below, in Utrecht, is used at a junction where private motor traffic cannot turn right, across people cycling.

The CROW manual also recommends that ASLs should only be employed in conjunction with a limited number of motor traffic stacking lanes - at the very most, two, and with separate feeder lanes for each motor vehicle stacking lane. It is rare to find ASLs that do not resemble the form in the photograph above. 

The Netherlands has, more broadly, moved away from ASLs as a form of junction treatment for cycling, preferring instead to employ separate signal phases at major junctions, as well as adopting more generally a policy of unbundling - removing motor traffic from certain routes, rendering signalling unnecessary.