Shared use of Advanced Stop Lines (ASLs)
4.4.1 The use of Advanced Stop Lines (ASLs) for cyclists at signal junctions is now widespread.
They are intended to provide a safe location for waiting cyclists, especially those wishing to make a right turn at a junction.
The Traffic Signs Regulations and General Directions (2002) (DfT 2002) clarified the legal position of such ASLs making it an offence for other vehicles to cross the first stop line and wait in the reservoir between the stop lines, except if unable to stop safely otherwise.
4.4.2 The shared use of specifically designed ASLs by cyclists and motorcyclists could provide similar benefits to motorcyclists as those experienced by cyclists:
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They offer a head start over other traffic, reducing the potential for conflict especially where turning movements are possible. |
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They allow motorcycles to be visible away from and in front of other traffic. |
4.4.3 There is an obvious potential safety benefit to cyclists themselves.Motorcycles are generally capable of greater acceleration than other motor vehicles; the risk of conflict is that much greater if motorcycles are placed directly behind them.
4.4.4 However, cycling representatives have raised concerns, arguing that the shared use of ASL would detract from the convenience and safety of making a trip by bicycle and that the facilities would no longer be being used for the purpose for which they were intended.
This implies that motorcyclists are less vulnerable than cyclists and do not need priority measures. Such concerns led to trials in the London Borough of Newham of shared use of ASLs.
These trials,monitored by the Transport Research Laboratory (TRL), have included attitudinal surveys both before the installation of the facilities and after, and a video survey.
The surveys showed significant illegal use of ASLs by a range of vehicles including motorcycles.
Conflict between pedal cycles and motorcycles was not identified as a problem although the trial sites only provide a limited range of conditions and there were few right turning manoeuvres.
4.4.5 The trials have highlighted a number of design issues regarding the shared use of ASLs, especially the provision of separate filter lanes for motorcycles providing direct access to the protected area.
There were particular concerns with motorcyclists rejoining other traffic as the signals change.
The early results of these limited trials have been encouraging (Tilly, A & Huggins, P 2003):
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Before the trial of the shared use of ASLs a majority of motorcyclists (77%) and cyclists (51%) were supportive of motorcyclists using ASLs. |
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After implementation 73% of motorcyclists thought the layout was an improvement along with 48% of cyclists. |
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80% of cyclists surveyed thought that the layout was better or unchanged and only 5% believed it had become worse. |
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Across all sites the number using the new ASL filter lane “after”was greater than the number that filtered on the outside “before”. |
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The number of motorcyclists filtering between the nearside kerb and queuing traffic fell from 13% to 6%. |
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There was no change in the number of cyclists managing to reach the front of the traffic queue. |
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The percentage of motorcyclists managing to reach the front of the traffic queue rose from 40% ‘before’ to 53% ‘after’. |
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Conflict between motorcyclists and cyclists did not arise. |
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Overcrowding was not an issue. |
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Motorcyclists would tend to wait on the right hand side of the ASL reservoir, cyclists on the left. Conflict could arise, however, between left turning motorcyclists and right turning cyclists.This was not an issue as the majority of movements were straight ahead. |
4.4.6 In view of the limited number of trial sites included in this study and the limitations on layout and traffic mix, there is a clear need for further trial sites,with local authorities being encouraged to apply for trial sites in their areas. In doing so the following points should be considered:
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A consistent approach should be adopted on a route so that both cyclists and motorcyclists know they share the facility and so that drivers will expect motorcyclists to filter to the ASL. |
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Motorcyclists are more likely than cyclists to access the feature from other than the nearside position. Access from the offside is feasible, given appropriate signing to inform all drivers and riders.The positioning of road-centre street furniture needs careful consideration in order to avoid last minute steering/braking corrections from riders. |
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Adequate and prominent advance signing is needed to alert both riders and drivers of the facility.
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Supplementary surface signing should be used sparingly - previous advice above about surface treatment and road markings is relevant. |
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All non-standard signs and markings require special authorisation from the appropriate authority. |
Shared use of bus lanes
 4.4.7 In the present situation, a typical urban road layout with a bus lane and a single all-purpose lane, during congested periods motorcyclists use the legal manoeuvre of “filtering” or passing to the right of stationary traffic.This presents three possible hazards:
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Potential conflict with oncoming traffic. |
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The risk of colliding with the opening door of an inattentive
car driver or passenger if the rider tries to reduce the above
risk by keeping close to stationary traffic. Car occupants
often use stationary periods in traffic to drop off passengers,
check the vehicle and so on. |
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Potential conflict with pedestrians crossing through
stationary traffic.Many pedestrians, having crossed an empty
bus lane and a stationary traffic lane, assume their next
hazard is traffic from the other direction, and do not look for
filtering motorcycles. |
4.4.8 Therefore the possible safety benefits of allowing motorcycles into bus lanes can be summarised as:
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Eliminating the potential for conflict with oncoming traffic while the rider is using the bus lane. |
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Reducing the potential for conflict between motorcycles and other traffic. Even if a car occupant opens a door on the nearside, they are more likely to check for permitted vehicles in the bus lane and in any case the motorcycle is likely to be in the centre of the bus lane, not close to the stationary traffic. |
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Reducing the potential for conflict with pedestrians because they will check for permitted vehicles before crossing the bus lane. |
4.4.9.1 Bus lane access by motorcyclists was first granted by Avon County Council in Bristol in the mid-1990s. Since then an increasing number of local authorities have allowed the shared use of bus lanes by cyclists, taxis and motorcycles. In 2007 The DfT produced a Traffic Advisory Leaflet~ TAL 2/07 The use of Bus Lanes by Motorcycles.
This revised the previous advice contained in Keeping Buses Moving (DETR 1997), against motorcycles normally being allowed into bus lanes and now recommends that local authorities consider such access
4.4.9.2 Signs permitting the use of bus lanes by motorcycles are not allowed without specific authorisation. Department for Transport (DfT) working drawings NP 958.4 and 959.4 give sign design details and special authorisation for signs will continue to be required until the additional variants are prescribed in any update to TSRGD".
4.4.10 Proposals to introduce shared-use bus lanes will often be met by objections.The arguments usually revolve around conflicts with cyclists, who are usually permitted to use bus lanes, and to a lesser extent reduction in benefits to buses. Concerns may also be raised over possible conflicts with pedestrians. For cyclists the concern would seem to stem from the differential speeds of bicycles and motorcycles; the smaller frontal profile of motorcycles, especially compared to buses, and the higher levels of traffic in bus lanes giving rise to at least the perception of greater risk and a less attractive cycling environment. For pedestrians, higher speeds and lower conspicuity underlie perceived safety concerns.
4.4.11 Experience of shared-use bus lanes in Bristol and subsequent trials by Transport for London (TfL) would seem to indicate that shared use of bus lanes can be introduced with little or no detrimental effect for other road users (TfL 2004). Interim data from these trials indicates:
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Reductions in motorcycle accidents between 0% and 31% at the trial sites, with no increase in overall accidents at any site. |
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Reductions in motorcycles using general traffic lanes of between 31% and 40% at the trial sites.There was no adverse effect on bus journey times. |
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In surveys 44% of cyclists reported that collisions and near misses they experienced when using bus lanes involved cars - this increased by 1% during the trial, and compared with 3% involving motorcycles, which again increased by 1% during the trial.The number of cars illegally using bus lanes fell during the trial, probably due to increased enforcement. |
4.4.12 The work has taken place against a background of the introduction of the London Congestion Charge, which has lead to an increase in motorcycles within the charge zone, along with a reduction in motorcycle accidents (TfL 2003).
The Government’s Motorcycle Strategy recognises that “although these studies have not finally concluded, the evidence so far suggests that there are no apparent safety disbenefits from allowing motorcycles to use bus lanes” and DfT will include consideration of the position on motorcycles as part of the review of LTN 1/97 in the light of the results of the research.
Road markings
4.4.13 The use of road markings needs careful consideration, especially within steering or braking zones.Used inappropriately they can force riders off the safest line, or if poorly designed or laid they can collect and divert water, adding to the problem of providing consistent grip.
The reduction in skid resistance over time or in wet conditions causes problems for motorcyclists.
Direction arrows and destination markings are of particular concern.
Often they are used on bends when, if they are needed at all, they could be better placed in an advanced position on a straight section of the road. Also they are likely to be re-laid on maintenance schedules, leading to layering and a significant up-stand from the surrounding surface; most road markings over 6mm in height are illegal with few exceptions, for example mini-roundabout domes.
Blacking-out redundant markings rather than burning or planing them off creates a higher up-stand with the added hazard of reduced skid resistance. In general,well positioned roadside advance warning or direction signs are preferable to surface markings. Count-down strips, rumble strips and coloured surface treatment should not be used close to or on bends where steering and braking is required unless consistent skid resistance is guaranteed. Lining or hatching used to reduce apparent carriageway width in urban situations can squeeze low-powered motorcycles and cycles into conflict with other traffic.
This should be balanced against any anticipated general safety benefits. |
