591,085 research outputs found
A Road Description Language for the Leeds Driving Simulator Guide (V1.0)
A driving simulator has recently been developed at the University of Leeds. Part of this work has been to provide a method of creating a wide variety of road networks to meet the demands of different experiments. This paper describes a simple language that specifies road networks and their appearance, including the definition of road markings, sign posts and roadside objects. It is intended for use by prospective users of the simulator facility in order that they could either build networks themselves or know what information is required for simulator staff to build a network for them
Multiple domination models for placement of electric vehicle charging stations in road networks
Electric and hybrid vehicles play an increasing role in the road transport
networks. Despite their advantages, they have a relatively limited cruising
range in comparison to traditional diesel/petrol vehicles, and require
significant battery charging time. We propose to model the facility location
problem of the placement of charging stations in road networks as a multiple
domination problem on reachability graphs. This model takes into consideration
natural assumptions such as a threshold for remaining battery load, and
provides some minimal choice for a travel direction to recharge the battery.
Experimental evaluation and simulations for the proposed facility location
model are presented in the case of real road networks corresponding to the
cities of Boston and Dublin.Comment: 20 pages, 5 figures; Original version from March-April 201
Scale Invariance in Road Networks
We study the topological and geographic structure of the national road
networks of the United States, England and Denmark. By transforming these
networks into their dual representation, where roads are vertices and an edge
connects two vertices if the corresponding roads ever intersect, we show that
they exhibit both topological and geographic scale invariance. That is, we show
that for sufficiently large geographic areas, the dual degree distribution
follows a power law with exponent 2.2 < alpha < 2.4, and that journeys,
regardless of their length, have a largely identical structure. To explain
these properties, we introduce and analyze a simple fractal model of road
placement that reproduces the observed structure, and suggests a testable
connection between the scaling exponent alpha and the fractal dimensions
governing the placement of roads and intersections.Comment: 6 pages, 10 figures; revision incorporates more rigorous statistical
analyses; matches journal versio
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