Category Archives: speed

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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What do posted speed limits show?

Engineers might think that the posted speed limit is based either on the design speed or on a measure such as the 85th percentile speed of traffic on an existing road,, and that theposted speed “is a speed limitation …. … Continue reading

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UK – 80 mile/hour speed limits?

According to an article in the UK’s Daily Mail on the 13th June (see here), the British government has plans to increase the speed limit on motorways from 70 mile/hr to 80 mile/hr (from 112 km/hr to 128 km/hr).

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Classification – motorways and speed (2)

In an earlier post (see here) I wrote:  Maybe there should be different sub-classes of motorway, such as

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Classification – motorways and speed

The wiki page on transport in Switzerland has a map which shows the A2 as a motorway running between Lucerne and Bellinzona and beyond. One conclusion that a highway engineer might reach is that, as this section of road is … Continue reading

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Bicycling: and London

The UK’s Independent newspaper has an article about cycling in London (link). It says that “The mayor of London has announced a billion-pound plan to revolutionise cycling in the capital in what could be seen as a model for urban … Continue reading

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Primary road classification

Terminology There are various definitions of road hierarchy and road classification. The basic difference (should) be that a hierarchy groups roads into different classes and then gives the classes some sense of ranking –  for example, in order of decreasing … Continue reading

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