Road design – road types

In recent posts I have discussed the idea of the “technical environment” for road design. One of the seven technical factors which I suggest describe this environment is “road type”. 

By road type I mean more than “road hierarchy” – in fact I believe that this particular term has lost much of its value. A road type refers to a road which by its nature and use needs specific design standards of its own. Examples might include port roads, gravel roads, or streets. In fact, separate design standards already exist for (at least) these three road types.

The following table is a first attempt to list road types. You will see that it includes “roads in tunnel” and “roads on bridges”. This is because some geometric design values are specific to these road types (for example, the normal value for the gradient of a motorway is not the same as the value of gradient for a motorway section in a tunnel).

road types 1

Comment

There already seems to be a move towards the development of geometric design standards for different road types, perhaps out of exasperation of the lack of appropriate detail in more conventional road design standards.

References

306  – UK, Lancashire CC: “Functional road hierarchy strategy”; 2002

726 – multi-country, UNECE “Trans European Motorway standards and recommended practice third edition”; 2002

1101 – Malawi, Roads Authority Malawi, “Preparation of a Pavement Design Manual and  Standard Bidding Documents   for Low Volume Sealed Roads in Malawi – Inception Report; 2013

1142 – Ireland, COFORD national council for forest research and development, “Forest road manual”; 2004

2211 – general, AFCAP, “Geometric design and safety for LVRR”, presentation by Dr. John Rolt, date ?

2273 – USA, Virginia DOT, “Virginia road design manual, A: geometric design”, 2015

Notes: ref. 306 mentions the road types indicated, the others indicate some detailed design guidelines

Advertisements

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).
This entry was posted in road design and tagged , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s