This paper uses geometry to evaluate major road proposals in cities with road networks consisting of orbital and radial routes. The type of geometry used is a development of the Karlsruhe or Moscow metric after the cities where it was identified, although the results have wider applicability. The paper begins with a detailed consideration of the relationship between route speeds, junction access and service areas. New urban patterns are presented using optimal space-filling techniques in which the aim is to maximise drive-time coverage with the minimum number of junctions. The method is then refined to allow for effects such as congestion and interstitial access. The results are then used in a case study to evaluate a well-known strategic road plan for London first proposed in the 1940s. There follows a general discussion about the policy and planning implications for London and further possible developments of the techniques presented.
Get full access to this article
View all access options for this article.
References
1.
Abercrombie, P. (1944) Greater London Plan. London: HMSO .
2.
Anjoumani, A. (1981) Market area analysis with a rectangular grid network , Environment and Planning A, 13, pp. 943-954.
3.
Christaller, W. (1933/ 1966) Die Zentralen Orte in Süddeutschland. Jena: Fischer. Trans by C. Baskin ( 1966) The Central Places of Southern Germany. Englewood Cliffs, NJ: Prentice-Hall.
4.
. Detr (Department Of The Environment, Transport And The Regions) (1998) Traffic speeds in central and outer London. Statistics Bulletin (98) 17. Government Statistical Service.
5.
Hathaway, P. (1974) Some applications of computer graphics to transportation planning, Greater London Intelligence Quarterly, 26.
6.
Hyman, G. and Mayhew, L. (1983) On the geometry of emergency service medical provision in cities, Environment and Planning A,15, pp. 1669-1690.
7.
Hyman, G. and Mayhew, L. (2000) The properties of route catchments in orbital radial cities, Environment and Planning B (in press).
8.
Klein, R. (1988) Voronoi diagrams and their applications (extended abstract), in: International Workshop on Computational Geometry , pp. 148-157. Berlin: Springer-Verlag.
9.
Lcc (London County Council) (1943) County of London Plan. London: Macmillan.
10.
Mayhew, L. (1981) Automated isochrones and the locations of emergency medical facilities in cities, Professional Geographer, 33, pp. 423-428.
11.
Mayhew, L. and Hyman, G. (2000) The impact of fast routes on urban travel geometry , Environment and Planning B, 27, pp. 265-282.
12.
Okabe, A., Boots, B. and Sugihara, K. (1992) Spatial Tessellations: Concepts and Applications of Voronoi Diagrams. New York: John Wiley.
13.
Richardson, H.W. and Anjoumani, A. (1978) The diamond city: The case for rectangular grid models. Paper presented at the Conference on Urban Transportation, Planning and Dynamics of Land Use, The Transportation Centre, Northwestern University.
14.
Tripp, H.A. (1942) Town Planning and Road Traffic. London: Edward Arnold.
