Following Manual for Streets and other local streets-oriented design
guidance, where does this leave road hierarchy?
By road hierarchy I mean the conventional set of road types such as
Primary Distributor, District Distributor, Local Distributor, Access Road.
I am asking this list because it can be difficult to track how this
is actually used, through published documents, since a document may
not mention hierarchy explicitly, but it may still be applied in some
way. Or, even if mentioned in a document, it is not always clear how
practitioners actually use it, when designing a road network.
I am interested in hearing of any cases where:
(i) Road hierarchy is still used - even if not expressed explicitly
in documents - if so, how is it applied?
(ii) Road hierarchy has 'evolved' where there may be new road types
added over and above the basic set - if so, what are they?
(iii) There is more than one set of guidance coexisting (e.g.
conventional engineering guidance + urban design guidance) - if so,
is the relationship between the two clear and consistent, and how are
they actually applied in practice?
(iv) Urban design style street types are used, but are expected
(implicitly or explicitly) to correspond to levels in the
conventional hierarchy (e.g. a Boulevard may be equate with a
District Distributor; a Mews may be an Access Road) - if so, how
does this work?
(v) Road hierarchy is applied to the "higher levels" (e.g. trunk
roads, county roads) while the lower level use a range of labels
(e.g. access street, high street, etc.) - if so, how is the high/low
level split decided?
(vi) Road hierarchy is no longer used - if so, what if anything has
I would be interested in hearing of any examples of these instances,
and how they work, especially in the UK (e.g. local authority
practice), but also non-UK examples where the equivalent of road
I will let the list know of any interesting results coming out of
this. This is part of an investigation into better integration /
articulation of road / street hierarchy / layout principles. This
research is part of the EPSRC funded project SOLUTIONS
(Sustainability Of Land Use and Transport in Outer NEighbourhoodS).
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Dr Stephen Marshall, Senior Lecturer, Bartlett School of Planning,
University College London
Wates House, 22 Gordon Street, London WC1H 0QB, Tel +44 20 7679 4884,
Fax +44 20 7679 7502
New journal: Urban Design and Planning www.urbandesignandplanning.com
New book: Cities Design & Evolution (Routledge, 2009)