Bicycle Network: Good Design Guides

Shared lane markings - friend or foe? [update]

21 February 2013. The practice of using sharrows, or shared lane markings, is a new world-wide trend in bike lane provision, including in Australia, but the latest evidence suggests they need to be implemented selectively, and with care.

 A recently released evaluation of shared lane markings on three local streets in Melbourne highlights the risks as well as advantages of shared lane markings.

On lower speed and low volume roads the markings can help bike riders and motor vehicles share road space.  One of the test sites though, showed an increase in conflict between bike riders and motor vehicles.

Incorrectly used, advisory markings can actually increase the risk of conflict or collision between cars and motor vehicles. 

There has been a proliferation of shared lane markings across Australia in recent years but no consistent application or guidance. The evaluation report casts doubt on the widespread use of advisory markings, in particular on higher speed roads and recommends:

"- exclusive bicycle lanes should be provided wherever possible; this can often be achieved through more effective reallocation of existing roadspace,
- where exclusive bicycle lanes cannot be provided sharrows are likely to be an attractive option where the following conditions are met:

• motorist speeds, volumes and roadway geometry is supportive of sharing between motorists and cyclists, and
• there is a reasonable safety case to be made that sharing will have net safety benefits (e.g. reduced car dooring risks or near roundabouts)"

Do advisory bicycle markings help you? We are interested in hearing your experiences, both as a driver and bike rider. Send us your photos and stories.

What’s the problem?

Some bike routes along existing roads have insufficient space for a designated bike lane or path. This means that bike riders must share lanes on the road with motor vehicles with no indication that motorists should expect them or where they should place themselves on the roadway (despite bicycles being legal vehicles on the road and the requirement to pass only when safe to do so). Bike riders following a route can find themselves following a bike lane which ends unexpectedly, leaving them with no choice but to share the continuing roadway with other vehicles.

Road upgrades with planned bicycle facilities that have not yet been installed may leave bike riders to share wide lanes with no markings to indicate their presence.

What are the risks?

Advisory bike markings do not have the legal status as bike lanes or paths so must be used with caution.

Without bicycle advisory markings bike riders may not have the confidence to ride out toward the centre of the lane where it may be less risky and motorists may not be aware of the potential presence of bike riders. This may lead to: 

• bike riders risking crashing by using the left edge of the road when it contains hazards such as drainage grates, rough kerbing and stationary vehicles and opening car doors. It may be safer to remain in or near to the centre of the lane particularly if it allows the rider to stay in full view of other vehicles and retain a consistent line not ducking in and out of the lane.
• motor vehicle drivers not giving bike riders enough room when passing or passing at speed. This can lead to serious crashes especially if the bike rider swerves to avoid a hazard and veers into the path of a vehicle travelling too close.

With bicycle advisory markings.  Incorrectly used, bicycle advisory markings may be ineffective or even increase the risk of a crash. Careful consideration of the volume, speed and mix of traffic is needed before they are installed. On busier roads, bike lanes or paths should be used if at all feasible. Sometimes this may require reassigning space on existing roads. Advisory markings may also be effective in reducing risk in the transition to "mixed zone" such as single lane roundabouts. 

Incorrectly used, advisory markings may give cyclists a false sense of safety especially motorists ignore the markings or don’t understand the requirement to share the road responsibly.

There is also a risk of advisory markings, particularly Wide Kerbside Lane markings,  being covered or obscured by stationary vehicles or traffic such that road users differ then in their expectations of the behaviour of others who may or may not have seen the advisory markings.

What is the solution?

Advisory bicycle markings are useful for marking shared space rather than separate space. They are advisory only and do not have any legal standing.  Bike lanes, enhanced bike lanes and separated paths are nearly always preferred on busier or higher speed roads (40km/h or over) where their is a high speed differential between bikes and cars. Where speeds and volumes of traffic are low, advisory markings can be useful in indicating and emphasising shared space. For instance in Portland and other North American cities they have been used to mark "bike boulevards" on quieter streets which have limited through motor vehicle traffic.  See providing for bicycles on roads.

Ideally advisory bicycle markings are complemented by measures to reduce vehicle speeds particularly on local residential roads. If supportive road conditions can be provided then advisory bicycle markings can be an attractive option. When all road users become more familiar with the markings and understand the sharing concept then conflicts would be expected to reduce.
 

Advisory bicycle markings currently take the form of: 

1. Wide Kerbside Lanes [WKL] can be used for wider kerbside lanes where motor vehicles can pass bike riders without changing lanes. They should be at least 3.7m wide on 60km/h roads and 4.3m wide on 80km/h roads. They comprise a bike logo with 3 or 4 white stripes marking the edge of a nominal bike lane. They are placed at 200 metre intervals and each side of intersections. These have been implemented on some major arterial roads to claim some road space for cyclists and to raise  awareness of motorists to the likely presence of cyclists. Trials showed that they helped increase the passing distance to bikes. Detailed specifications can be found in VicRoads  Cycle Notes No. 13 ‘Wide Kerbside Lane Markings’.

WKLs on higher speed roads do not suit the novice riders who are not comfortable riding alongside busy motor vehicle traffic and so have a limited role in encouraging more people to ride.

2. Sharrows ("SHared ARROW") or shared lane markings (SLMs) are a more recent advisory road marking developed in North America (well Europe really) and are now being used more extensively in Melbourne to designate bike routes on low speed and traffic volume roads primarily residential streets. Sharrows have also been used with mixed success to alert motorists on short sections of busy roads which provide a crucial link in a bicycle network. Sharrows generally take the form of two broad arrows, close together and sometimes with a bike logo within the arms of the arrow.  (photo at left  from http://www.clrp.cornell.edu/q-a/49_Sharrows/49_Sharrows.htm)

In Los Angeles a study (see link at right) supported using Shared Lane Markings (SLMs) and noted that SLMs are pavement markings installed to direct bicyclists where to ride on roadways shared with motor vehicles. The study found that SLM improved the passing behaviour of motor vehicles on some streets trialled. The SLM is typically used along corridors where there is not sufficient width for bike lanes, but where there is a need to offer guidance to bicyclists in terms of positioning, and awareness to motorists in terms of bicyclist presence. In addition, the marking is intended to reduce the chance of bicyclists striking abruptly opened doors of motor vehicles on a shared roadway with on-street parallel parking.  

3. Bicycle Logo or bicycle awareness zones (BAZs) :  The concept of an advisory road marking also extends to simply placing a bicycle logo in the middle of a car lane on a low volume street.  Advisory road markings such as Bicycle Logos or BAZs do not need to meet WKL guidelines as to lane widths as they only indicate a road corridor where other road users can expect to encounter bikes and so are expected to drive slowly, safely and to use common sense and courtesy. BAZs are used extensively in Queensland to help bike riders and motor vehicles share lanes but are often hard up against parked cars. They have been effective in improving overtaking behaviours on some narrow bridges and "The BAZ without edge line marking is the preferred treatment for narrow bridges" where bike lanes can not be provided - see study.

What do the guidelines say?

There is limited guidance on the use of advisory bike lanes apart from wide kerbside lane markings. The Austroads Guides (see excerpt at right) give widths and guidance on the use of wide kerbside lanes and note that exclusive bike lanes are always preferable. Guidelines for Wide Kerbside Lane Markings can be found on VicRoads Cycle Note  Wide Kerbside Lane Markings   VicRoads intends that the WKL's provide an indication to motorists and cyclists that such a lane is wide enough to be shared by motor vehicles and bicycles side by side. The width of the WKL having been specified according as to the posted speed zone be it 60, 70, or 80kph (see table at bottom of this page). The markings are only advisory and are not mentioned in the Australian Road Rules.

The guidance on other advisory treatments is very limited. The Austroads Guides notes that have "no regulatory function" and that the"form of treatment is a matter for local jurisdictions". As such the use of advisory treatments is not consistent across States or even across local councils within Australia. Queensland makes wide use of Bicycle Awareness Zones, usually marked in yellow, while other States use a variety of markings, some of which replicate the sharrow markings used in North America. The recent review of shared lane markings on residential streets by CDM research for VicRoads gives some guidance on their use (see link at right).

Austroads 'Local Area Traffic Management recommends [6.2.1.1] inter alia that in designing a Local Area Traffic Management (LATM)  'to aim for a speed environment that is sympathetic to cyclists as well as other road users.' Streets that have been traffic calmed such as in a LATM are most suited to the use of  advisory road markings. In [6.2.1.6 ] 'Squeezepoints and locations where drivers may attempt to negotiate severe deflections at excessive speeds, exposing cyclists to vehicles at higher speeds should not be created". 

Standards
There are no standards for marking of bicycle advisory markings across Australia. In the USA, the State of California was the first to adopt standards for the installation of the SLM (Shared Lane Markings). Standards for the use of the marking are as follows:
The shared roadway bicycle marking shall only be used on a roadway (Class III Bikeway (Bike Route) or Shared Roadway (No Bikeway Designation) which has on-street parallel parking. If used, shared roadway bicycle markings shall be placed so that the centers of the markings are a minimum of 3.3 m (11 ft) from the curb face or edge of paved shoulder. On State highways, the shared roadways bicycle marking shall be used only in urban areas. Section 9C.103(CA), CA MUTCD

What do we say about the guidelines?

The Austroads Guides gives only limited guidance on the use of advisory markings. They are clear that wide kerbside lane markings and other advisory treatments are only advisory and marked bicycle lanes are always preferred on busier roads. There needs to be more guidance on other advisory treatments such as sharrow markings and bicycle awareness zones so that their usage is consistent across jurisdictions and traffic regimes. The guidelines need to make it clear that advisory markings have only limited use and are usually only effective in slower speed conditions where complementary measures help "calm" the street so it can be shared by bike riders and motor vehicles.  

Examples, good and bad.

	Bad Blyth St, Brunswick East Advisory lane markings similar to wide kerbside lane marking have been use along this busy street but have not been supplemented by any traffic calming measure that would reduce the risk of collision when bikes pass parked cars.
	Better Johnson St, Richmond These Bicycle advisory logos in one direction (bike lanes in the other) are supplemented by speed humps and narrow lane widths.
	Better Groom St, Clifton Hill Bicycle advisory logos are used to indicate a local bike route using a quiet local street.
	Poor Wide kerbside lane marking, Victoria St, Richmond. The wide kerbside lane markings are only visible during peak hours when parking is not allowed. The markings are hard to see amongst the parking lanes and do little to encourage less confident riders.
	Bad Wide kerbside lane markings on this busy roads (photo from Cyclenotes 13) provide minimal (though measurable) benefit to bike riders and are not suitable for novice bike riders. Reassigning space to make room for a painted bike lane or providing an off-road path are preferable options.
	Good The Strand in Moonee Ponds. The road is too narrow for bike lanes unless parking is removed. Speed humps and raised crossings help reduce speed. Bikes are not forced to travel close to parked cars and encouraged to share the lane with motor vehicles.

 Below - Table 4.2 from Cycling Aspects of Austroads Guides, 2011