Armando Cartenì

A Quality-Based Approach to Public Transportation Planning: Theory and a Case Study

ABSTRACT Methodologies for defining standard quality indicators are important to assess service quality in public transport. The article proposes a method to integrate EU service quality standards in the transport planning process. It also investigates the effects of a set of large-scale transport policies in Campania region, Italy, in terms of service quality and ridership variations. Results of 10 years-long transport policies (€3,115 million invested) shows an impressive increase in both service quality and ridership. The article also compares perceived and measured service quality indicators for a new high quality metro line. Results point to new perspectives in modelling users’ travel behavior and related quality measures.

Tactical and strategic planning for a container terminal: Modelling issues within a discrete event simulation approach

Abstract In this paper different microscopic discrete event simulation models for a container terminal are presented. The focus is on the best approach to adopt to simulate handling activity time duration and on which level of detail should be pursued with respect to different planning horizons that a decision maker have to face. The models share the same logical architecture but differ in the approaches pursued to estimate handling activity time duration. Terminal operations were broken down into elementary activities pursuing a level of disaggregation not usual in the literature; time duration of each elementary handling activity was modelled through a stochastic approach, distinguishing container type; validation was carried out with respect to different planning horizons (real-time/short-term, long-term) through the definition of local and global indicators and a before-and-after analysis. Modelling issues are discussed for tactical and strategic planning, and operational guidelines are given.

Estimation of urban traffic conditions using an Automatic Vehicle Location (AVL) System

The aim of this paper is to develop an Information Extension Model (IEM) which uses location data of bus fleets (AVL data) to estimate road traffic conditions and provide input for implementing control strategies. The IEM consists of three sub-models: the Link Traffic Condition Model (LTCM), the AVL Adaptation Model (AVLAM) and the Network Traffic Condition Model (NTCM). The first provides road traffic conditions as a function of mass-transit traffic conditions in the case of shared lanes, the second provides mass-transit traffic conditions as a function of AVL data, and the last provides road traffic conditions over the whole road network as a function of mass-transit traffic conditions. The IEM (and its sub-models) were developed and calibrated in the case of real dimension networks and some tests were performed on a trial network. Numerical results show the effectiveness of the proposed method since it allows a reduction in travel demand estimation errors.

Stochastic equilibrium assignment with variable demand: Theoretical and implementation issues

Recently, it has been pointed out that transport models should reflect all significant traveler choice behavior. In particular, trip generation, trip distribution, modal split as well as route choice should be modeled in a consistent process based on the equilibrium between transport supply and travel demand. In this paper a general fixed-point approach that allows dealing with multi-user stochastic equilibrium assignment with variable demand is presented. The main focus was on investigating the effectiveness of internal and external approaches and of different algorithmic specifications based on the method of successive averages within the internal approach. The vector demand function was assumed non-separable, non-symmetric cost functions were adopted and implementation issues, such updating step and convergence criterion, were investigated. In particular the aim was threefold: (i) compare the internal and the external approaches; (ii) investigate the effectiveness of different algorithmic specifications to solve the variable demand equilibrium assignment problem through the internal approach; (iii) investigate the incidence of the number of the links with non-separable and/or asymmetrical cost functions. The proposed analyses were carried out with respect to two real-scale urban networks regarding medium-size urban contexts in Italy.

Greening the transportation sector: a methodology for assessing sustainable mobility policies within a sustainable energy action plan

The reducing use of fossil fuels and greenhouse gas emissions is one of the main aims of urban planning. These objectives directly involve urban activities which are responsible for 80% of energy consumption and CO2 emissions and indirectly the transport sector which contributes in the range of 20%–40% in terms of consumption of fossil fuels and emissions of greenhouse gases and particulate matter. In this context, the simulation, the evaluation and the implementation of sustainable mobility policies are a crucial challenge for decision makers and analysts. At this aim, the paper proposes an integrated modelling framework which, following a bottom-up approach, combines a transportation simulation model (demand, supply and supply-demand interaction) with traffic fuel consumption and vehicle emission models. The aim was twofold: 1) specify and implement a modelling framework characterised by a level of detail not usual in literature and able to estimate fuel consumptions and greenhouse gas emissions with respect to any transportation scenario; 2) investigate the effects of different transport policies by applying the system of models. The proposed methodology was implemented to the urban context of Salerno municipality (Southern Italy), within the development of the sustainable energy action plan.

Simulating Container Terminal Performances: Microscopic vs. Macroscopic Modelling Approaches

Most of the existing contributions for container terminal analysis follow approaches based on optimization models, that are mainly useful to support strategic decisions about terminal container configuration. Many others contributions follow the simulation approach, which allows a detailed analysis but may lead to computational problems and is rather computer demanding, especially when resulting models are used to support optimization. This paper investigated the prediction reliability of two different approaches to container terminal simulation: microscopic and macroscopic. The former simulating single container movement, the latter simulating container flows movement. The microscopic model was a discrete event simulation model, the macroscopic model was a dynamic discrete time based (space-time) network assignment model. Both modelling approaches were implemented and compared taking advantage of some significant investment made by the Salerno Container Terminal (Italy) between 2005 and 2011. In particular, disaggregate (microscopic) and an aggregate (macroscopic) simulation models implemented in 2005 were validated with a large set of data acquired in 2011 after some structural and functional terminal modifications. Through this analysis it was possible to analyze the prediction reliability of both simulation approaches and to draw some operational guidelines.

Acceptance and equity in advanced path-related road pricing schemes

The impact of the transport sector range between 20% and 40% in terms of consumption of fossil fuels and emissions. Many urban areas are trying to adopt planning strategies aimed at reducing the car usage and their emissions reaching a sustainable mobility. The introduction of a toll for the use of a road infrastructure and/or a service is one of the most common Transportation Demand Management policy. The development of the Intelligent Transportation System (ITS) technologies allow extending and applying these pricing schemes (both for passenger and for freight) in several different and most rational (sustainable) ways, connecting the price both to the individual characteristics of the trip and to the type of vehicle used. The aim of the study is to propose an original transport-related acceptance & equity measure useful for enlarging both the consensus and the equity in the design of a road pricing scheme. Results of the research underline the importance in introducing acceptance&equity measures as an additional design criteria in road pricing schemes, jointly with the traditional ones (e.g. road traffic congestion reduction and pollutant reduction).

Particulate matter concentrations in urban metro systems: Case studies and a literature review

Many experimental results round the worls have measured elevated concentrations of fine particles in underground metro systems, with significant implications for human health caused by the protacted exposition to Particulate Matter (PM). On the basis of these considerations, the aim of this research is to propose an original literature review with respect to the particulate matter concentrations (PM10 and PM2.5) both for underground and for ground-level urban metro system.

Calibration and transferability of travel time cost functions for urban and suburban roads: a case study in Italy

Cost functions are commonly used in traffic assignments to account for the effects of congestion on road link performances. Despite their influence on assignment results, not many functions are available for estimating travel times on urban or suburban roads, in particular, on roads belonging to historical cities or on roads surrounded by urbanized areas. The solution usually adopted either does not consider the effect of congestion on the travel time, or is based on the Bureau of Public Roads’ (BPR) function. Nonetheless, traffic flow disturbances like side-parking can appreciably affect link travel time resulting in a rise in congestion, especially in the roads of ancient centres. The aim of this paper is threefold: first, to calibrate and validate a travel time function for urban road links; secondly, to investigate the transferability of the cost function to a set of suburban roads; finally, to re-calibrate the cost function in the same suburban context to investigate possible improvements. The cost function included the effect of side-parking, secondary streets and road winding on the worsening of performance due to congestion. Cross-validation results showed the robustness, the transferability and the applicability of the calibrated cost function. Keyword: cost function, travel time, calibration.

Effects Of A New Inter-city RailwayInfrastructure On Transport Mode Competition

This paper focuses on a real case study concerning a reorganization of the railway system of the Salerno province (in the Campania region). In order to analyze the feasibility of a new railway connection a two-step procedure is proposed. First, a sub-set of feasible scenarios is identified through a stated preferences analysis, then the most effective scenario has been sorted out by modelling the whole transportation system. The transportation system has been simulated by dividing the study area into three sub-areas and for each sub-area a different mathematical model has been used. For each scenario, the demand variation has been assessed, and the impacts on the supply system performances have been evaluated.