Traffic Management Concept for New Inner Semi-circular Ring Road in Belgrade
M Osoba, B Stanic, University of Belgrade, YU
The alternative solutions of new arterial road of Belgrade street network are discussed. The focus is at access control provided through road physical layout, type of connection to surrounding network and traffic control system based on ITS.
Belgrade is the capital of Serbia, a city with 1.5 million inhabitants, which together with the reference urban hinterland has almost 2 million inhabitants. Components of radial character dominate functionally in the geometrically irregular configuration of the core street network, and previous monocentric urban structure contributed to formation of strong tradition of attractiveness of the city centre.
Capacitative limitation of the traffic network of the old city core, insufficient parking capacity and conflict with transit movements represent the key components of the traffic problem of the city. It is expected that this problem will be considerably alleviated with radical improvement of public mass transit (by construction of Light Rail Transit System) and construction of the Inner Arterial Semi-Circular Road.
The Inner Arterial Semi-circular Road (IASR) is the future arterial street which, for the Belgrade street network, should provide capacitative and dynamic potential required for anticipated traffic demand in the decades to come. It is planned as a fast urban road stretching along the fringe of a broader city centre, which frees the central city area from excess transit flows and, for its origin and destination movements, provides effective connection with urban hinterland and city access routes. The first phase of IASR construction consists of 2 km of relatively lighter route through regular and systematically designed street network in the new part of the city, from 1.5 km long bridge over the Sava River and from its connection with strong radial corridor linking two approach routes and large urban hinterland with the city centre.
In order that IASR retains attributes and character of a city artery it was necessary to provide appropriate approach control related to adjacent street network. This was initially determined by adequate alignment and selective physical connection with the elements of surrounding street network. The most delicate and loaded link was the contact with the existing radial city arterial street on the other bank of the Sava River.
Two alternative solutions were evaluated in detail both from the aspect of costs of their total physical implementation and from the aspect of traffic process efficiency such solutions should serve. One solution is based on the classical concept of completely grade-separated intersection (similar to grade-separated intersections on motorways), and the other solution is based on the concept of intersection containing both grade-separation and accesses to adjacent light-controlled network. Reality and functionality of both solutions have been checked and functionally evaluated for the forecasted traffic loads by microscopic simulation.
The second component of approach control - which is more important in dynamic sense- is applied ITS traffic management system along IASR, combined with management solution for observed intersections. Proposed was a rational, functional and multistage management solution, which implies compatibility with the adjacent management systems on the network, open architecture and concept suitable for technological upgrading and development of hardware and software components. At the same time, the proposed solution is integrated into future traffic management system on the Belgrade city street network, the design and implementation of which is in progress.
The paper will present all relevant numerical and other indicators which illustrate functionality and quality of the observed alternatives and explain the suggested decision.
Association for European Transport