Bruno Santos

Integrating Equity Objectives in a Road Network Design Model

The traditional approach to the road network design problem focuses on the optimization of network efficiency under a given budget. Generally, this leads to the improvement of roads next to the largest population centers, where travel demand is higher. Such results are not consistent with sustainable development principles, since the dissimilarities between the welfare of large and small centers will tend to increase. Nevertheless, equity issues were rarely taken into account in road network design. Moreover, all existing studies rely on a single equity measure. In this paper equity concerns in transportation planning are reviewed briefly, and a comparison of alternative equity measures is presented. Three equity measures were selected and incorporated into an accessibility-maximization road network design model. The three equity measures reflect different perspectives on equity: accessibility to low-accessibility centers, the dispersion of accessibility values across all centers (Gini coefficient), and the dispersion of accessibility values across all centers and across centers in the same region (Theil index). The implications of adopting each of these equity measures are illustrated through application of the optimization model to three random networks.

Interurban road network planning model with accessibility and robustness objectives

Abstract Road network planning (or design) problems consist of determining the best investment decisions to be made with regard to the improvement of a road network. In this paper, we propose an optimization model for long-term interurban road network planning where accessibility and robustness objectives are simultaneously taken into account. Three network robustness measures were defined to assess different robustness concerns: network spare capacity; city evacuation capacity; and network vulnerability. The results that may be obtained from the application of the model are illustrated for three random networks. Special attention is given to the implications of adopting each one of the robustness measures upon the optimum solution provided by the model.

Multiobjective Approach to Long-Term Interurban Multilevel Road Network Planning

This article presents a multiobjective approach to long-term interurban multilevel road network planning. In addition to the efficiency objectives dealt with in most of the literature where the subject is addressed, the approach takes into account robustness and equity objectives. For achieving the objectives, two types of action can be performed: the construction of a new road of a given level; and the upgrading of an existing road to a higher level. The approach is consistent with the planning framework of the highway capacity manual, using the concept of level of service to assess traffic flow conditions. The application of the approach is illustrated for a case study involving the main road network of Poland.

Integrating Vehicle Emission Modeling with Activity-Based Travel Demand Modeling: Case Study of the Greater Toronto, Canada, Area

An initial attempt is made to quantify vehicle emissions in the Greater Toronto Area (GTA) in Canada by exploiting travel information provided by activity-based 24-h models rather than conventional trip-based models. For this purpose, travel activity inputs to the Canadian version of the MOBILE6.2 model (MOBILE6.2C) are generated by relying on the travel demand modeling capabilities of the Travel Activity Scheduler for Household Agents (TASHA), a next-generation activity-based model of travel demand for the GTA. Additional input data supplied to MOBILE6.2C are obtained from Canadian sources and by running traffic assignment (using EMME/2) on the trip distribution matrix generated by TASHA. The integration of MOBILE6.2 with TASHA has provided estimates of the time of day that vehicle emissions occur. TASHA provides an explicit representation of trip starts and ends, which results in improved engine start emissions. Overall, because TASHA provides a better behavioral framework for modeling travel than conventional trip-based models, it is expected to lead to better emissions estimates. Such an effort also provides insight and experience that will be used later in the integration of TASHA with more advanced emission models, thus refining the reliability of practical tools that can be used to assess the environmental sustainability of policies.

A prototype tool for dynamic pluvial-flood emergency planning

Due to the increased frequency of extreme rainfall events caused by climate change, flooding in urban areas is becoming increasingly recurrent. Nevertheless, mitigation and response actions to flood events are still defined according to the best judgments of civil protection authorities, based on their experience and on simple flood modelling tools. In this paper we present the methodological structure of an innovative prototype tool for dynamic pluvial-flood emergency planning. The tool is aimed at helping civil protection authorities (and the population) in the preparation, mitigation and response to flood events. The 2009 flood in the Agualva village (Terceira Island, Azores, Portugal), is used to exemplify the models calibration and to illustrate the prototype capabilities. The results highlight the importance of considering a dynamic approach in the design of pluvial-flood emergency planning.

Modeling of Human Exposure to Benzene in Urban Environments

Urban areas characterized by high spatial and temporal variability in air pollution levels require implementation of comprehensive approaches to address exposure of individuals. The main objective of this study was to implement a quantitative assessment of individual exposure to benzene in urban environments. For this purpose, ExPOSITION model based on a global positioning system (GPS) tracking approach was applied to estimate individual exposure in different microenvironments. The current investigation provides an application example and validation of the modeling approach against personal and biological exposure measurements collected during the measurements campaign. The probabilistic approach using the Johnson system of distributions was implemented to characterize variability of indoor concentrations. The results obtained for daily average individual exposure to benzene corresponded to mean levels of 1.6 and 0.8–2.7 μg/m3 in terms of 5th–95th percentiles. Validation of the model results against several personal exposure samples collected for the selected individuals revealed a Pearson’s correlation coefficient of .66. This modeling approach explicitly addressed the temporal and spatial variability in the exposure and established a source–receptor relationship.

Solutions to mitigate power quality disturbances resulting from integrating intermittent renewable energy in the grid of Porto Santo

Due to the electricity increase consumption in recent decades, the rising price of fossil energy and uncertainty associated with its supply, there has been a growing concern for energy efficiency and the exploration of endogenous renewable energy sources. These changes are intended to promote greater security in supply, to reduce energy bills as well as greenhouse gas emissions. If this effort make sense anywhere, it is even more significant in islands where conventional primary energy is considerably more expensive. Given the intermittence of renewable sources such as solar and wind, it becomes essential to search for effective solutions to integrate them into the grid. This work describes the methodology for choosing an effective solution for the integration of intermittent generation in the island of Porto Santo.