2 research outputs found
Traffic optimization in transport networks based on local routing
Congestion in transport networks is a topic of theoretical interest and
practical importance. In this paper we study the flow of vehicles in urban
street networks. In particular, we use a cellular automata model to simulate
the motion of vehicles along streets, coupled with a congestion-aware routing
at street crossings. Such routing makes use of the knowledge of agents about
traffic in nearby roads and allows the vehicles to dynamically update the
routes towards their destinations. By implementing the model in real urban
street patterns of various cities, we show that it is possible to achieve a
global traffic optimization based on local agent decisions.Comment: 4 pages, 5 figure
A minimal model for congestion phenomena on complex networks
We study a minimal model of traffic flows in complex networks, simple enough
to get analytical results, but with a very rich phenomenology, presenting
continuous, discontinuous as well as hybrid phase transitions between a
free-flow phase and a congested phase, critical points and different scaling
behaviors in the system size. It consists of random walkers on a queueing
network with one-range repulsion, where particles can be destroyed only if they
can move. We focus on the dependence on the topology as well as on the level of
traffic control. We are able to obtain transition curves and phase diagrams at
analytical level for the ensemble of uncorrelated networks and numerically for
single instances. We find that traffic control improves global performance,
enlarging the free-flow region in parameter space only in heterogeneous
networks. Traffic control introduces non-linear effects and, beyond a critical
strength, may trigger the appearance of a congested phase in a discontinuous
manner. The model also reproduces the cross-over in the scaling of traffic
fluctuations empirically observed in the Internet, and moreover, a conserved
version can reproduce qualitatively some stylized facts of traffic in
transportation networks