Simplification of standards (1)

When you go on a journey, you begin by finding yourself a  long way from your destination. However, as you move on the destination becomes closer and perhaps clearer- it can focus in from a town to a street, to a house, even to a room in the house.

I thought the same thing would happen with engineering design. That is, if I wanted to check out something such as how to calculate horizontal radius, I would find myself zooming in to one specific formula or set of values – and that would be it. In fact the opposite happens – the more I looked into horizontal  radius, the more detailed and extensive became the information and the competing options. For example, I thought horizontal radius was a function of speed, friction and superelevation. But

  1. Speed depends also on vehicle type
  2. Friction depends on tyre condition, which depends on tyre pressure
  3. Superelevation even depends on the dominant type of weather
  • and there are also “hidden”features such as “cost” and “factor of safety”.

In an earlier post on superelevation( here) I identified 17 features which affect superelevation, so maybe there are as many as 40 features which affect horizontal radius (say 3 * 17 less 11 to allow for duplication).

Suggestion (1)

Maybe a new design approach would begin by listing the features which can influence / or be influenced by a geometric design parameter. For example, for horizontal radius these might include:

suggestion 1


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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