Category Archives: comparative geometrics

Bike lanes (4) definitions

You might think that it would be possible to get a general understanding of bike lanes if you start by checking out definitions of what they are. There are problems with this: even if we only look at documents which … Continue reading

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Bike lanes (2) “style sheets”

In the previous post on bike lanes I said that it would be good to prepare an overview of cycle lanes, so that designers can pick the design best suited to their project; and I suggested that tThere are at … Continue reading

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Bike lanes (1) a structure of types

Bike 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 … Continue reading

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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 … Continue reading

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Notes on “design speed”

Speed – and in particular design speed – is a key parameter in determining values for a number of highway geometric features in highway design. Examples include horizontal radius and stopping sight distance. There also seems to be a  relationship between … Continue reading

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NMT in developed countries

Following on from the last post I came across a document by Piet Rietvald of the Netherlands which was published in 2001. The document is called “Biking and Walking: The Position of Non-Motorised Transport Modes in Transport Systems” (ref. 2254). … Continue reading

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NMT in developing and developed countries

There is a page on the Internet (here) which lists different modes of transport, grouped under the headings of: Intermediate Means of Transport (IMT) Non-Motorised Transport Modes (NMT) The two lists partly contain the same modes, so they could be … Continue reading

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Non-Motorised Transport – “bring back the old”

Photo: Dr. Placide Badji A lot of the discussion about road transport concentrates on the problems of road space for cars and trucks. It is probably fair to say that- even in developing countries – transport plans firstly look to … Continue reading

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Road gradient – (1) definition and vehicle performance

Definition of gradient In terms of the vertical alignment of a road, one of the primary design parameters is gradient. A good definition of gradient is given in (ref. 148), which says:

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Simplification of standards (4) primary and local documents

In 2011 Los Angeles County, USA published the “Model streets design manual” (ref. 2206). The document is worth reading in itself. But in terms of the simplification of its standards the website (here) gives an interesting explanation of its purpose:

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