Advanced Stop Lines (ASLs)

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ASLs help cyclists at junctions
ASLs help cyclists at junctions
Headline Messages: 
  • Advanced Stop Lines (ASLs, also known as cycle boxes) are some of the cheapest, most cost-effective and popular ways to give cyclists visible priority at junctions, where around 70% of cyclists’ collisions occur. They help cyclists control their own safety as they prepare to manoeuvre through the junction, by positioning themselves where they are clearly visible to the drivers behind them.
  • ASLs should be progressively introduced on all traffic-light junction arms, with possible exceptions for busy high-speed roads with high quality off-road cycle facilities. Decent width ‘feeder lanes’ should enable cyclists to reach the ASLs without being obstructed by queuing traffic.  In some situations, it is beneficial to provide a feeder lane between or to the right of the general traffic lanes, either instead of or in addition to one on the left hand side, or to provide no feeder lane at all. Cyclists should be warned not to use left-hand side feeder lanes to undertake lorries, although we know of no evidence to date that providing these lanes increases the risks of collisions with left-turning motor vehicles.
  • CTC recommends the progressive introduction of coloured surfacing for ASLs and their feeder lanes, focusing particularly on those junctions where cyclists most need to assert their priority to avoid being cut up.
CTC View (formal statement of CTC's policy): 
  • There should be a presumption in favour of providing Advanced Stop Lines (ASLs) on all arms of all signalised junctions.
  • Highway authorities should progressively introduce ASLs at all signalised junctions, making site-specific alterations to the junction layout as required. Exceptions may be made on high speed (40mph or above) where there are existing off-carriageway facilities that meet cyclists’ needs, or where a decision is taken to provide these.
  • The Government should pursue moves to clarify and amend the legislation covering cyclists’ access to and use of ASLs; and make civil enforcement of ASLs possible.
  • Each location needs to be carefully assessed to determine the most appropriate site specific layout, having regard for the line of approach taken by cyclists and their turning movements. The safety benefits of different ASL layouts should be kept under review.
  • ASLs should be provided with at least one feeder lane on any junction arm where the traffic volumes and speeds merit the provision of a cycle lane (or cycle use of a bus lane), in accordance with CTC’s campaigns briefing on on-road cycling (forthcoming).
  • On any junction arm with more than one entry lane, consideration should be given to providing a feeder lane away from the kerb (i.e. either between or to the right of the general traffic lanes).  This may be either in addition to or instead of a feeder lane to the left of the general traffic lanes. The safety benefits of different ASL layouts should be kept under review.
  • Feeder lanes should be at least 1.5m wide, preferably 2m, especially where cycle flows are high. General traffic lanes on junction approaches can be reduced to 2.5m to accommodate this, and 2.25m is acceptable on quieter streets with little or no bus or lorry traffic.
  • CTC recommends the progressive introduction of coloured surfacing for ASLs and their feeder lanes. Priority should be given to locations with multiple general traffic lanes and/or complex conflicting movements between cyclists and motorised traffic.
Download full campaigns briefing: 
Publication Date: 
March 2014
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  • Patron: Her Majesty The Queen
  • President: Jon Snow
  • Chief Executive: Paul Tuohy
  • Cyclists' Touring Club (CTC): A company limited by guarantee, registered in England no.25185. Registered as a charity in England and Wales No 1147607 and in Scotland No SC042541


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