Distribution of Value of Time and Ways to Model Value of Time in Long-Range Planning Models

As managed lanes (ML) become more integrated in regional urban networks with existing general purpose (GP) lanes, the distribution of travelers’ value of time (VOT) is becoming more important for transportation planning agencies to quantify in order to accurately predict future travel patterns. Since travelers’ VOT varies depending on a multitude of factors, this study investigates ways that we can determine the VOT distribution of a region from existing travel data as well as effective ways that we can model VOT using traffic assignment algorithms. In networks with available link volumes and toll data on segments where travelers have the option of choosing to stay on the GP lanes or entering a ML facility, a VOT distribution can be inferred assuming that travelers who enter the ML choose to do so based on a certain “threshold” VOT. When modeling these VOT distributions, errors are observed in the traffic assignment results when both the continuous nature of VOT distributions are discretized, and when varying toll values are assumed to be constant. Specifically in the context of TransCAD software, link travel time errors appear to be much less significant than flow errors when tested on a nine node network. Additional experimentation on larger regional networks is needed to verify the significance of these errors and their impact on predicted travel patterns.Civil, Architectural, and Environmental Engineerin

Simulating use cases for the UAH autonomous electric car

2019 IEEE Intelligent Transportation Systems Conference (ITSC), Auckland, New Zealand, 27-30 Oct. 2019This paper presents the simulation use cases for the UAH Autonomous Electric Car, related with typical driving scenarios in urban environments, focusing on the use of hierarchical interpreted binary Petri nets in order to implement the decision making framework of an autonomous electric vehicle. First, we describe our proposal of autonomous system architecture, which is based on the open source Robot Operating System (ROS) framework that allows the fusion of multiple sensors and the real-time processing and communication of multiple processes in different embedded processors. Then, the paper focuses on the study of some of the most interesting driving scenarios such as: stop, pedestrian crossing, Adaptive Cruise Control (ACC) and overtaking, illustrating both the executive module that carries out each behaviour based on Petri nets and the trajectory and linear velocity that allows to quantify the accuracy and robustness of the architecture proposal for environment perception, navigation and planning on a university Campus.Ministerio de Economía y CompetitividadComunidad de Madri

If Alonso was Right: Residual Land Price, Accessibility and Urban Attraction

This study investigates whether accessibility shapes the attractiveness of residential land as predicted by theory. A spatial hedonic analysis is conducted for the metropolitan area of Berlin, Germany, using a large set of georeferenced property transactions and micro-level data. We find that the nuclei of residential land price and employment density gradients are separated by approx. 10 km, which essentially contradicts theoretical implications. Also, environmental externalities arising from the residential composition or the building structure and density in the neighborhood are more important determinants than access to the city center, which, if at all, impacts negatively on residential land prices. Moreover, a new gravity-based accessibility indicator is employed that incorporates the effective distribution of employment as well as the rapid transit network architecture in order to disentangle the effects of proximity to employment opportunities from a more general urban attraction effect. After controlling for accessibility, we find a negative effect of urban attraction, respectively an effect of urban repulsion, indicating a relatively higher attractiveness of peripheral locations. This effect is partially counterbalanced by the benefits arising from access to employment opportunities that are, although relatively dispersed, more concentrated within downtown areas. In the tension between both forces, the land price gradient tends to be, if at all significant, positive. After all, we conclude that if transport costs are very low, commuting costs lose their role as the most striking determinant of land price. These results are robust to spatial dependency.Accessibility, gradient inversion, land price, urban attraction, Berlin