Narrow Results

This paper develops Lárraga and Alvarez-Icaza (LAI) cellular automata model which is based on safe human reaction. Vehicles are moving at two single-lane streets with periodic boundary condition and pass from intersection point via yielding mechanism avoiding collision. The model characteristics and fundamental diagrams have been obtained by Monte Carlo simulations. Our results suggest that LAI model with yielding mechanism is able to reproduce the realistic acceleration and deceleration capabilities, which are desired parameters. Moreover, the plateau region in total current illustrates the hardness of the yielding mechanism and limited speed strategy, which is applied near the intersection point.

We study a family of deterministic models for highway traffic flow which generalize cellular automaton rule 184. This family is parameterized by the speed limit m and another parameter k that represents a "degree of aggressiveness" in driving, strictly related to the distance between two consecutive cars. We compare two driving strategies with identical maximum throughput: "conservative" driving with high speed limit and "aggressive" driving with low speed limit. Those two strategies are evaluated in terms of accident probability. We also discuss fundamental diagrams of generalized traffic rules and examine limitations of maximum achievable throughput. Possible modifications of the model are considered.

Statistical mechanics points out as fluctuations have a relevant role for systems near critical points. We study the effect of traffic fluctuations and the transition to congested states for a stochastic dynamical model of traffic on a road network. The model simulates a finite population that moves from one road to another according to random transition probabilities. In such a way, we mimic the traffic fluctuations due to the granular feature of traffic and the dynamics at the crossing points. Then the amplitude of traffic flow fluctuations is proportional to the average flow as suggested by empirical observations. Assuming a parabolic shaped flow-density relation, there exists an unstable critical point for the road dynamics and the system can perform a phase transition to a congested state, where some roads reach their maximal capacity. We apply a statistical physics approach to study the onset congestion and we characterize analytically the relation between the fluctuations amplitude and the appearance of congested nodes. We verify the results by means of numerical simulations on a Manhattan-like road network. Moreover we point out the existence of oscillating regimes, where traffic oscillations back propagate on the road network, whose onset depend sensitively from the traffic fluctuations and that have a strong influence on the hysteresis cycles of the systems when the traffic load is modulated. The comparison between the numerical simulations and the empirical traffic data recorded by an inductive-loop traffic detector system (MTS system) on the county roads of the Emilia Romagna region in Italy is shortly discussed.

In this paper we propose a Regional Internet Exchange (RIX) scheme for MENA countries intra-regional traffic, compared with the existing situation for Internet service provision. The RIX architecture is proposed, implemented, and evaluated using simulation. Simultaneous comparative performance evaluation of Internet service provision for the existing and the proposed scenarios are presented. It is focused to measure utilization, message delays, access time and client perceived latencies performance metrics. The study shows that the proposed scheme results in less international bandwidth utilization and it reduces significantly the access time and most importantly it is inherently cost-effective.

Non-commercial Land Ports of Entry (LPOEs) are unique transportation facilities controlling the ingress and egress of passenger vehicles from Mexico to the United States and vice versa. The calibration of microscopic traffic simulation models of non-commercial LPOEs requires a deep understanding of operational processes and driving behavior at these facilities. This paper provides a methodology to guide modelers in calibrating microscopic traffic simulation models of non-commercial LPOEs. The methodology establishes a common framework for modeling operational processes and traffic operations. Moreover, the methodology includes the value of four state variables that characterizes operations of passenger vehicles at non-commercial LPOEs. These variables are speed, acceleration, deceleration, and headway. The authors evaluated this methodology using the Otay Mesa non-commercial LPOE as a case study. Results showed that this methodology could be potentially used to model non-commercial LPOEs along the US–Mexico border and other border regions worldwide.