Bicycling 3 / 5: Cycle lane widths

Here is the short version of one method for calculating what the width of a cycle lane should be.

Method for calculating width of a cycle lane

1. Decide what type of cycle lane you are designing

In this example, the lane on the side of a carriageway which has raised kerbs, and with no parking lane.

2.  Decide if cycle traffic will be low or high

Higher cycle traffic flows will need to be wider both to increase capacity and to allow bicycle overtaking. In this example, traffic flow is low.

3. Decide what the width of bicycle and rider is

Writing in terms of Dutch legal provisions, Theo Zeegers (Ref. 1899) says that a ” bicycle (on two wheels ..) may legally have a maximum width of 75 cm”. But he goes on to say that “a three wheeled bicycle can be wider, but not wider than 150 cm” and that “it should be noted that a trailer behind a bicycle on two wheels may be 1 metre wide“. In this example, a 1m width would cover both trailers and some of the path wobble and tilt which bicycle riders show.

4. Calculate the width of a bicycle lane from

• a) the shy distance from the edge of the road
• b) the width of the vehicle
• c) the inter-vehicle distance between bicycle and vehicles in the adjoining traffic lane

Where here

• a) = 500mm (see e.g. Ref. 1899, also Ref. 1250 example 15)
• b) = 1000 mm
• c) = 750 mm (see e.g. figure 235 in 1617)

The resulting width of the cycle lane is then 2.25m.

Does a 2.25m cycle lane seem too wide?

The UK’s Cambridge Cycling Campaign has a web page (here) which quotes eight different sources which recommend a cycle lane width of 2m. The footnotes on the page include the comment that:

“It is not acceptable to provide narrow cycle lanes in order to give motor traffic more room or greater priority. As made clear in the Lancashire cycling design standard, narrow cycle lanes increase the level of hazard and intimidation to which cyclists are exposed, and are almost always worse than providing no lane at all”.

Health warning

The width of 2.25m suggested here for a cycle lane applies to

• An on-road lane next to the edge of a kerbed road
• Where cycle traffic flows are low
• Where the lane is not close to a junction
• Where the lane is not used for bicycle overtaking
• Where the lane is used for one-way bicycle traffic flow

In other circumstances – for example, high cycle traffic flows – the cycle lane width would have to be greater.

Comment

The London cycle network – design manual (Ref. 1117) in table 2.2 suggests widths for an advisory cycle lane which range from 0.8m to 1.2m. It sounds like these are far too low to be safe (see for example this blog post and this blog post, both from 2011). If there is not enough road width for a safe cycle lane and traffic flows and / or speeds are too high for a shared bicycle / motorised vehicles traffic lane then the authorities should

• ban bicycles from this road and
• construct a solution for a safe cycling route

References

1117 – UK, “London cycle network – design manual”,  RB Kingston upon Thames; 1998

1250 – USA, “Bicycle compatibility index, a level of service concept, implementation manual”, FHWA 1998

1617 – Germany, Wolf et al, “Strassenplanung”, Werner Verlag 2013

1899 – Netherlands, Theo Veegers, “About bicycle path widths”, CROW 2004

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About roadnotes

Robert Bartlett is an international consultant with over 30 years of professional experience as a highway and traffic engineer with leading companies and organisations in several countries, including Germany, China (Hong Kong), Qatar and the UK. Specialised in urban studies, transport and the use of GIS, research has included new ideas on subjects such as the study of social justice using GIS, the dimensions of vehicles, and comparative geometrics (highways and transport).
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2 Responses to Bicycling 3 / 5: Cycle lane widths

1. Jeremi Rychlewski says:

Since you are going international, I have to comment that in some cities a cycle lane (contrary to a cycle way) of 2,25 m would quickly become a … parking for cars. A generally accepted width of a cycle lane for a singular bike is 1,50-2,00 m.

• roadnotes says:

Hallo Jeremi. The link I added in the post to the Cambridge Cycling campaign page shows a table with recommended widths of 2.0m / minimum 1.5m. Its better to have 2.0m for the safety of cylists. if you want to allow space for bicycles overtaking each other the bike lane might have to be wider, and as bike flows increase, the lane might have to be even more wide. Then maybe either cycle lanes are covered by traffic regulations as are bus lanes, or there is no cycle lane and cars have to travel at around 20 km/hr behind the bicycles – at least, if there is no space for an off-carriageway lane and no change of separate bicycle / motor traffic routes. I would not be surprised if increasing bicycle traffic leads to frustrated motorists.