The Viennese diagonal
Urban cycling needs appropriate infrastructure! A new organizational element for road intersections may help: The Viennese diagonal aims especially at cycle highways and allows a “one-step crossing” in contrast to the traditional and widespread “two-step-crossing”, where cyclists need to wait at least one period at traffic lights and are being confronted with limited space and sharp turns.
High quality and high priority bicycle connections are frequently issued demands by cyclists – and hardly ever met with current intersection situations and changes in bike infrastructure setups.
Generally, two types of routings can be distinguished: two-sided and mono-directional vs. one-sided and bi-directional. External boundary conditions, e.g. topography or space constraints, often lead to changes from one type to the other or one side to the other along one route. At intersections, they are very often connected with “two-step crossings” which reduce comfort due to sharp turns, little space and travel delays for cyclists (Fig. 1).
We therefore propose the Viennese diagonal as a comfortable and viable solution for providing high quality cycling routes.
The Viennese diagonal is a diagonal cycle lane alignment and aims at high priority bike routes with a large number of cyclists in comparison to normal numbers of cyclists and cars, e.g. the cycling super highways being introduced to London (Transport for London, 2011).
The Viennese diagonal’s principle given in Fig. 1c is already a well-established layout known to transport systems design, e.g. from railroads changing sides of a road (Fig. 2). Private car users are therefore used to a similar type of infrastructure.
To sum it up, the newly introduced bicycle infrastructure entails the following:
Benefits: It is a highly visible and present prioritization of cycling without (significant) reduction of road-flow utilizing similarities to public transport prioritization schemes;
Challenges: It is a new concept and not yet introduced to the road code or professional’s guidelines in Austria and elsewhere;
Minor disadvantages: additional traffic light programming and roadway maintenance for on-pavement markings are necessary.
The Viennese diagonal was developed as a common idea by Tadej Brezina, Nick Ibesich and Martin Niegl.
Category: Urban Planning and Urban Design