Bike lanes (1) a structure of types

bike lanes 1-1Bike lanes – in the general sense of “road space for use by cyclists” – have been around for quite a while. There is a Wikipedia article on the history of cycling infrastructure which says:

“The history of cycling infrastructure starts from shortly after the bike boom of the 1880s when the first short stretches of dedicated bicycle infrastructure were built ….”
But bike lanes have had a difficult history – at times, both motorists and cyclists objected to them. The same Wikipedia article says that In the 1930’s local branches of a UK cycling organisation held “mass meetings to reject the use of cycle tracks and of any suggestion that cyclists should be forced to use such devices”.

Today they are very much in fashion, and road designers have available a large number of standards and guidelines on their design. New problems are that there are so many different standards that it is difficult to get an overview of them; and they do not use the same terminology (even between documents published in the same language). Here are just a few terms for bike lanes taken from some English-language design standards / guides (seethe list of references below).:

Here are some terms used to describe different types of bike lane:
Separated bike lane (SBL)
One-way SBL Pair
Two-way SBL
Bicycle facilities
Shared lane markings
Shoulder bikeway
Conventional bike lane
Buffered bike lane
Cycle Track: Oneor two-way, at grade, protected with parking
Cycle Track: One or two-way, raised with mountable curb
Cycle Track: One or two-way, curb separated
Multi-use, off-street path
Bicycle boulevard
On-road bikeway
Buffered Bike Lanes (buffered from parking)
Buffered Bike Lanes (buffered from vehicles)
Shared travel lane (25 mph)
Separated path
Cycle track
Raised bike lane
Shared use path
Multi-use trail
Shared streets Cycle‐specific Infrastructure on Shared Streets
‘Bicycle Streets’ / Mixed Priority Treatment
Vehicle Restricted/‘Pedestrianised’ Areas
Home Zones
Segregated streets
Mandatory Cycle Lanes
Hybrid Cycle Lanes
Advisory Cycle Lanes

Simplifying method (a): structured listing
How can we prepare an overview of cycle lanes, so that designers can pick the design best suited to their project? There are at least four different ways:
a) By defining a structured listing of bike lane types
b) By “good practice” style sheets
c) By standardising terms
d) By defining bike lane types

For (a), a possible starter “structured listing” is included below. Probably it can only be developed further if we understand what the terms mean, and we can only do that if we understand how they are defined. For notes on (b,c,d) see the next blog posts.

bike lanes 1-2

• Ref. 986 ODOT Highway Design Manual Chapter 13 Pedestrian and Bicycle (USA 2012)
• Ref. 1937 Cardiff cycle design guide (UK 2011)
• Ref. 2372 Massachusetts separated bike lane planning and design guide 2015 (USA 2015)
• Ref. 2472 Washington County Bicycle facility design toolkit (USA 2012)


The first figure is from Massachusetts separated bike lane planning and design guide 2015 (USA 2015)

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UK new road design standards

Highways England recently announced they are to release an updated set of road design standards in 2018 which will be used across the United Kingdom.

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Design standards

A textbook on highway engineering once said that there are three topics to consider in road design: the vehicle, the user and the road. We can add two more to this list:

  • Road standards – There are very many of these. They may contradict each other, be out of date or simply wrong
  • The person designing the road – who may misread the road standards, or make human errors when preparing the design

So for example, any investigation of a road traffic accident should include a look at the design of the road, the road standards used in preparing it, and perhaps the person / or organisation which designed it.

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More notes on road design standards (1)

Many countries publish “standards“, notes, advice and requirements related to the geometric design of roads. But as I have argued before (see for example here) there are too many of these standards. What makes life more difficult for engineers is that most of these standards suffer from one or more of the following problems:

  1. Traceability

A standard may suggest values for a parameter such as “side friction” – but does not say where the values come from. For all the reader may know, they may be based on research made in another country almost a century earlier. The reader should be able to trace back the suggested values to their original source.

  1. Completeness

The information presented may be incomplete. To take “side friction”  as an example again, perhaps the standard only gives values for one vehicle type, or the accompanying notes forget to mention that correction factors were applied to observed values.

  1. Terminology

The standard may not define the terms which it uses. For example, perhaps the values suggested for side friction refer to wet , surfaced roads, and are “maximum side friction factors accepted for design purposes” (or desirable maximum, or whatever).

  1. Inconsistency

Occasionally a standard may give different values for the same parameter, either internally or where the standard is part of a series of documents.

  1. Findability

Sometimes, suggested values are hidden in a dense jungle of explanatory notes, or spread through different sections of the same document; or the document may not have a table of contents. This makes it difficult to find values you are interested in.

  1. Technical

Many of the parameters involved in road geometric design can be associated with different design approaches, theories and concepts. Some of these approaches and concepts may be out of date, or doubtful, or perhaps not yet widely accepted.

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Chile’s Road design manual updated

Chile’s Roads Department, part of the Ministry of Public Works, has just updated its Manual de Carreteras. The documents can  be downloaded free of charge from (but you need to register and log in).

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60 mile/hour speed limit?

Around four years ago I wrote that, according to an article in the UK’s Daily Mail (see here), the British government had plans to increase the speed limit on motorways from 70 mile/hr to 80 mile/hr (from 112 km/hr to 128 km/hr).

Recently the same newspaper reported that the British government now has plans to reduce the speed limit on motorways from 70 mile/hour to 60 mile/hour (see here).

Not sure how these policy changes fit in with the idea of consistency in design.

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“Findability” and road design standards

I have just published some notes on “side friction”, which you can download (for example) from Academia. The document has a “discussion” section which in part looks at how current design standards fail their users. Examples of these failures include inconsistent terminology and lack of traceability.

Another one, which I plan to add to the next version of the document, is “findability“, in the sense of “is the information I am looking for, easy to find?” To take two examples, in a Tanzanian standard (ref. 294) the information is easy to find, whereas in the USA’s AASHTO document (ref.831) it is not so easy to find.

Of course, it does not follow that, even if the information is easy to find, the information is correct.

294 Tanzania, Road Geometric Design Manual (2011 ed), Ministry of Works 2011
831 USA – A policy on the geometric design of highways and streets 2011, AASHTO 2011

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Road design and older drivers

blog post 2

There used to be a saying that road designs were a function of the road, the vehicle and the driver. It now appears that there are different types of driver, and some standards are appearing which suggest different values for design when the driver type is an “older driver” (ref. 2439) or a member of the “aging population” (ref.2441). It appears the USA document was first published in 1998.


Ref. 2441 USA, Handbook for designing roadways for the aging population 2014 , FHWA, 2014
Ref. 2439 Austroads, Road safety environment and design for older drivers, 2000

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ARRB resources

blog post 1

The ARRB is the Australian Road Research Board. Its website says that it “exists to serve the research needs of its Members, and maintain its reputation as a national interest, applied research organisation. Hence, our vision is born: to deliver an ‘adaptable connected future’ for every road user”.

The ARRB has a Knowledge Base, which is a searchable library of documents on topics such as road and bridge design. Many of the documents can be downloaded. The service seems to work, and to be quite useful. Here is the link to the Knowledge Base:

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London – Doubtful project development procedures

On the 7th April 2017 the Independent newspaper reported on what it described as Dame Margaret Hodge’s “damning” independent review of the London Garden Bridge project. This project, as London’s official website says: “….is a proposed footbridge and public garden over the River Thames, linking Temple with the South Bank. The project is being led by the Garden Bridge Trust”.
Dame Hodge’s report (which can be downloaded from this link) draws a number of severe conclusions about the control of the project, including:

On value for money
“Decisions on the Garden Bridge were driven by electoral cycles rather than value for money. From its inception when there was confusion as to its purpose, through a weak business case that was constructed after contracts had been let and money had been spent, little regard has been had to value for money”.

On escalating costs
“The project has already used £37.4 million of public money and the agreement to underwrite cancellation costs by the Government could bring the bill to the taxpayer up to £46.4 million. I believe it is better for the taxpayer to accept the loss than to risk the additional demands if the project proceeds”.

On conduct and procedure of Transport for London and the Greater London Authority
“The procurements subject to this review comprised one contract that was awarded to Heatherwick Studio for design and consulting services and one contract that was awarded to Arup for engineering and project management services. These were not open, fair or
competitive procurements and my review revealed systemic failures and ineffective control systems at many levels”.
(In the above quotes, I have highlighted parts of the texts)

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