Pierluigi Coppola

An adaptive freeway traffic state estimator

Real-data testing results of a real-time nonlinear freeway traffic state estimator are presented with a particular focus on its adaptive features. The pursued general approach to the real-time adaptive estimation of complete traffic state in freeway stretches or networks is based on stochastic nonlinear macroscopic traffic flow modeling and extended Kalman filtering. One major innovative aspect of the estimator is the real-time joint estimation of traffic flow variables (flows, mean speeds, and densities) and some important model parameters (free speed, critical density, and capacity), which leads to four significant features of the traffic state estimator: (i) avoidance of prior model calibration; (ii) automatic adaptation to changing external conditions (e.g. weather and lighting conditions, traffic composition, control measures); (iii) enabling of incident alarms; (iv) enabling of detector fault alarms. The purpose of the reported real-data testing is, first, to demonstrate feature (i) by investigating some basic properties of the estimator and, second, to explore some adaptive capabilities of the estimator that enable features (ii)-(iv). The achieved testing results are quite satisfactory and promising for further work and field applications.

Real-Time Freeway Network Traffic Surveillance: Large-Scale Field-Testing Results in Southern Italy

This paper reports on some large-scale field-testing results of a real-time freeway network traffic surveillance tool that has recently been developed to enable a number of real-time traffic surveillance tasks. This paper first introduces the related network traffic flow model and the approaches employed to traffic state estimation, traffic state prediction, and incident alarm. The field testing of the tool for these surveillance tasks in the A3 freeway of 100 km between Naples and Salerno in southern Italy is then reported in some detail. The results obtained are quite satisfactory and promising for further future implementations of the tool.

LUTI Model for the Metropolitan Area of Santander

This article presents a land use and transport interaction model (LUTI model) to simulate the overall equilibrium of an urban system. The proposed system of integrated models combines random utility theory with hedonic regression techniques and a transport model with equilibrium between supply and demand to estimate the location of population, economic activities, and average real estate prices in different zones within an urban system. The LUTI model was applied to the metropolitan area of Santander (Spain) to check its base year goodness of fit and therefore its ability to predict the impacts of introducing different transport policies. In the case of Santander, the property price and population/economic activity location submodels showed sensitivity to the different accessibility and transport characteristics of each zone, and the model as a whole provided a good degree of fit.

Simulation-based evaluation of advanced public transportation information systems (APTIS)

Despite the great success and the broad diffusion of Advanced Public Transportation Information System (APTIS), there is a lack of studies, in the literature, investigating “systematically” how and to what extend such systems can affect network performances and travelers’ path choices. In this paper, with respect to the realistic case study of the city of Naples (South-Italy), we investigate the impacts of information offer in a Public Transportation (PT) network under different network condition, i.e. irregular vs. regular services, congested vs. un-congested lines. The focus is on APTIS deploying shared en-route descriptive information. The presented results are based on the simulation of the three main components of the PT system, namely the network performances, the information provider (i.e. the Operation Control Center) and the travelers. The simulation of these components and their interaction is achieved using different modeling approach: the schedule-based approach for the network representation and the traffic assignment, a statistical model based on the Kalman filter for the prediction of the link travel times within the simulation period, and behavioral discrete choice models, following the Random Utility Theory, for simulating travelers’ behavior.

New High-Speed Rail Lines and Market Competition

The new 1,000 km of high-speed rail (HSR) line between Turin and Salerno, Italy, were completed in 2009, and new service by the Italian railways state-owned company Trenitalia started in December of that year. Furthermore, in anticipation of the European open-access regulatory framework, starting from April 2012, the new HSR private operator Nuovo Trasporto Viaggiatori entered the market and is competing with the incumbent Trenitalia. This is the first case of large-scale competition between nonsubsidized HSR operators on the same line (i.e., infrastructure managed by the state-owned company, Rete Ferroviaria Italiana). This study provides an overview of the short-term dual effects of the opening of the new HSR line operating with a single service provider (between 2010 and 2012) and of the competition between the two operators starting from 2012. Before-and-after effects on services, prices, and attracted and generated demand based on several data sources, including ad hoc surveys and a system of mathematical models, are presented. Results suggest that the dual effect of new HSR lines and the opening of competition in the market has been producing a significant increase in HSR supply (+94% of trains per day) and demand (+98% of passenger-kilometers per year). The market share in the HSR core area increased about 20% at the expense of air and automobile modes. About 13.8 million extra trips per year were estimated in 2013 with respect to rail demand in 2009 (8.3 million diverted from other modes and 5.5 million induced trips) despite the severe economic crisis faced by the country in the same period.

Intra-Period (Within-Day) Dynamic Models for Continuous Services

To simulate important aspect of some transportation systems (e.g. demand peaks, temporary capacity variations, temporary over-saturation of supply elements, and formation and dispersion of queues) a new class of models, referred to in the literature as Dynamic Traffic Assignment (DTA) models, have been recently developed. Although Dynamic Traffic Assignment to networks is a relatively new research subject, a great number of models have been proposed in the last two decades. These can be divided in two main classes according to the typology of service they aim at simulating. These are continuous services, considering transportation services available at any time and accessible from several points, such as the services offered by individual road modes (car, bicycle etc.), and scheduled services simulating services available only at certain times and that can be accessed only at certain locations (terminals, stations, airports etc.). In this paper the focus is on continuous services. Models proposed in the literature are reviewed and classified according to basic assumptions on the flow structure, i.e. whether a continuous or a discrete approach is followed, and on the representation of time (discrete vs. continuous). A general modeling framework consisting of supply, demand, and demand-supply interaction models, and including most of the existing specifications is presented both for the discrete time-discrete flow and continuous time continuous flow cases.

Impactos de la accesibilidad mediante transporte público en los valores inmobiliarios: una comparación entre las ciudades de Roma y Santander

Existe evidencia empirica que avala la hipotesis de que incrementos en la accesibilidad a oportunidades pueden impactar positivamente en los valores inmobiliarios. Sin embargo, esta capitalizacion de los beneficios de la accesibilidad puede ser desigual en distintas areas de estudio. En esta investigacion se estiman modelos hedonicos y modelos hedonicos espaciales en dos areas urbanas para comparar si existen diferencias en los impactos de la accesibilidad utilizando transporte publico. Las dos areas de estudio seleccionadas han sido una ciudad media sin grandes problemas de movilidad (Santander, Espana) y una gran ciudad con elevados problemas de congestion (Roma, Italia). Los modelos hedonicos estimados han considerado la posible existencia de efectos espaciales, habitualmente presentes en los datos inmobiliarios, que pueden generar dependencia en los residuos de los modelos hedonicos. La accesibilidad se ha medido utilizando dos tipos de indicadores: de accesibilidad relativa y gravitatoria. Los resultados permiten afirmar que la accesibilidad fue un factor positivo en el precio de los valores inmobiliarios de ambas ciudades, si bien en el caso de Santander unicamente de forma relativa al centro urbano. Estos resultados son relevantes de cara a implementar politicas de captura del valor que permitan financiar nuevos proyectos de transporte publico. DOI: http://dx.doi.org/10.4995/CIT2016.2016.4065

Large-Scale Field Testing of a Real-Time Freeway Network Traffic State Estimator in South Italy

This paper addresses a large-scale field test of a real-time freeway network traffic state estimator that was recently developed. The related network traffic flow modeling and state estimator design are first outlined. The test of the estimator for the A3 freeway of 100 km between Naples and Salerno in South Italy is then reported in some detail. The obtained results are deemed quite satisfactory and promising for further future implementations of this traffic state estimation tool.