Dynamic Modeling for Intelligent Transportation System Applications

Special Issue on Dynamic Modeling for Intelligent Transportation System Applicationspostprin

Characterizing Three Engineering Systems Methods for Supporting Regional Strategic Transportation Planning Applied to Freight Systems

A systems perspective for regional strategic transportation planning (RSTP) for freight movements involves an understanding of Supply Chain Management (SCM). This paper starts from the premise that the public sector needs to enhance economic development in the form of providing and ensuring the operation of sufficient network capacity for freight needs but at the same time secure the region’s long term environmental and societal well being. The need for long-term integrated transportation planning that is sensitive to supply chain needs and environmental nuances can be supported by the use of engineering systems methodologies. Here we demonstrate the use and potential of three such methods: Design Structure Matrix (DSM), System Architecture (SA) and System Dynamics in support of a transportation planning process that integrates SCM considerations into RSTP

Making road freight transport more sustainable : Insights from a systematic literature review

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Platooning of connected automated vehicles on freeways: a bird’s eye view

A platoon of connected automated vehicles (CAVs) is defined as a group of CAVs that exchange information, so that they can drive in a coordinated way, allowing very small spacings and, still, travelling safely at relatively high speeds. The concept of vehicle platooning is not new. Scientific articles on platooning have been published since the 1970s, and the first large-scale pilot test on vehicle platooning was carried out in the mid 1990s in California. By 1992, the first vehicle platooning experiments were successfully concluded, and the four-vehicle platoon capability was demonstrated for visitors on the I-15 HOV lanes in San Diego in 1994. The main purpose of these early research works was to improve traffic efficiency and reduce vehicle consumption, as well as to develop the existing technology, which represented a strong limitation at the time. Precisely, the development of new technologies and communications in the last decade has given a new impetus to the research on vehicle platooning on freeways, as one of the most promising forms of cooperation among CAVs. These recent studies have extended the analysis beyond traffic efficiency, including safety, sustainability, business productivity, among other objectives. In this context, today, there are many scientific publications on vehicle platooning with different purposes, scopes, scenarios, and based on a wide diversity of vehicles and technologies (i.e. regular or segregated lanes, cars or trucks, vehicles with different SAE levels, etc.). In order to organize and consolidate the existing knowledge on the field, a comprehensive and systematic review must be performed. The present work represents a first approach to this ambitious objective. First, platooning is conceptualized in order to facilitate its analysis and comparison among studies. Second, key publications on platooning are analyzed to determine the most significant impacts that can be expected from its implementation. Finally, some important research gaps and disparate findings on the topic are identified.This research has been partially funded by the Spanish Ministry of Economy, Industry and Competitiveness, within the National Program for Research Aimed at the Challenges of Society (grant ref. PID2019-105331RB-I00).Peer ReviewedPostprint (published version

Exploring multiple eco-routing guidance strategies in a commuting corridor

The introduction of eco-routing systems has been suggested as a promising strategy to reduce carbon dioxide emissions and criteria pollutants. The objective of this study is to scrutinize the impacts of an eco-routing guidance system on emissions through the use of a case study in a commuting corridor. This research aims at assessing the potential environmental benefits in terms of different pollutant emissions. Simultaneously, it addresses the extent of variations in system travel time that each eco-routing strategy implies. The methodology consists of three distinct phases. The first phase corresponded to the adjustment of a micro simulation platform of traffic and emissions with empirical data previously collected. Secondly, volume-emission-functions (VEF) were developed based on the integrated modelling structure. Finally, different scenarios of traffic flow optimization were performed at the network level based on a simplified assignment procedure. The results show that if the traffic assignment is performed with the objective of minimize overall impacts, total system environmental damage costs can be reduced up to 9% with marginal oscillations in total system travel time. However, if drivers are advised based on their own emissions minimization, total system emissions may be higher than under the standard user equilibrium flow pattern. Specifically, environmentally friendly navigation algorithms focused on individual goals may tend to do divert traffic to roads with less capacity affecting the performance of the remaining traffic. This case study brings new insights about the difficulties and potentials of implementing such systems

Modeling the efficiency of a port community system as an agent-based process

We present an agent-based method which makes use of reinforcement learning in order to estimate the efficiency of a Port Community System. We have evaluated the method using two weeks of observations of import containers at the Port of Brisbane as a case study. Three scenarios are examined. The first scenario evaluates the observed container delivery by individual shipping lines and estimates the consignments allocated to the various road carriers based on optimizing the individual shipper's total logistics cost. The second scenario implies that, in the optimum case, all agents (shipping lines and road carriers) communicate and cooperate through a single portal. The objective of cooperation is in sharing vehicles and creating tours to deliver shipments to several importers in order to reduce total logistics costs, while physical and time window constraints are also considered. The third scenario allows for some agents to occasionally decide to act based on individual costs instead of total combined logistics costs. The results of this study indicate an increase in the efficiency of the whole logistics process through cooperation, and the study provides a prototype of a Port Community System to support logistics decisions