A Model of Risk-Sensitive Route-Choice Behavior and the Potential Benefit of Route Guidance

In this paper, we present a simulation-based investigation of the potential benefit of route-guidance information in the context of risk-sensitive travelers. We set up a simple two-route scenario where travelers are repeatedly faced with risky route-choice decisions. The risk averseness of the travelers is implicitly controlled through a generic utility function. We vary both the travelers' sensitivity toward risk and the equipment fraction with route-guidance devices and show that the benefits of guided travelers increase with their sensitivity toward risk

The Role of Spatial Interaction in Social Networks

This article addresses the role of spatial interaction in social networks. We analyse empirical data describing a network of leisure contacts and show that the probability to accept a person as a contact scales in distance with similar to d (-aEuro parts per thousand 1.4). Moreover, the analysis reveals that the number of contacts an individual possesses is independent from its spatial location and the spatial distribution of opportunities. This means that individuals living in areas with a low accessibility to other persons (rural areas) exhibit at average the same number of contacts compared to individuals living in areas with high accessibility (urban areas). Low accessibility is thus compensated with a higher background probability to accept other candidates as social contacts. In addition, we propose a model for large-scale social networks involving a spatial and social interaction between individuals. Simulation studies are conducted using a synthetic population based on census data as input. The results show that the model is capable of reproducing the spatial structure, but, however, fails to reproduce other topological characteristics. Both, the analysis of empirical data and the simulation results provide a further evidence that spatial interaction is a crucial aspect of social networks. Yet, it appears that spatial proximity does only explain the spatial structure of a network but has no significant impact on its topology

Cadyts a free calibration tool for dynamic traffic simulations

This article reports on the realization and on first applications of the Cadyts (Calibration of dynamic traffic simulations) calibration tool. The presented first version of Cadyts calibrates disaggregate demand models of dynamic traffic assignment simulators from traffic counts. The tool is broadly applicable in that it (i) makes only very mild assumptions about the calibrated simulators workings and (ii) allows for various modes of technical interaction with the simulation software. The article provides a both conceptual and technical overview of the tool and exemplary demonstrates its applicability to two different traffic microsimulators

Going beyond path flow estimation -- calibration of arbitrary demand dimensions from traffic counts

An operational framework for the demand calibration in DTA microsimulations from traffic counts is presented. The calibrated choice dimensions comprise but are not constrained to route choice, departure time choice, and destination choice. The mathematical background of the methodology is outlined and results from a large real-world application are given. The flexibility of the proposed approach is demonstrated in terms of a freely available software implementation (http://transp-or2.epfl.ch/cadyts/) that is designed to interface with a broad class of DTA microsimulations

Macroscopic Network Loading of Microscopic Network Demand

This article presents a computationally efficient technique for the macroscopic (equation-based) network loading of microscopic (simulation-based) travel demand. It combines the expressive power of microsimulations as sampling tools for highly heterogeneous demand segments with mathematically well-understood macroscopic network loading procedures. The presented experimental results demonstrate the efficiency and precision of the approach even for large and complex scenarios. This work is intended to contribute to the understanding and application of microsimulation techniques in the context of mathematically motivated dynamic traffic assignment procedures