Francesco Russo

Measures for Sustainable Freight Transportation at Urban Scale: Expected Goals and Tested Results in Europe

Around the world, interest in urban and metropolitan goods movements is increasing because they account for a substantial share of traffic in urban and metropolitan areas. In this context, many city administrators have implemented measures to mitigate the negative effects of freight transportation. Starting from an analysis of existing studies relative to freight policies implemented at the urban scale in Europe, this paper proposes a general classification of measures adopted at the urban scale and an analysis of expected goals and tested results. Each described measure is analyzed by considering the temporal reference scale (strategic, tactical, and operative) of the actors and decision makers involved. Each measure pursues and is linked to one or more expected goal, and the empirical results obtained in the European cities and demonstrated by specific indicators representing the goal are presented.

AN ASSIGNMENT MODEL WITH MODIFIED LOGIT, WHICH OBVIATES ENUMERATION AND OVERLAPPING PROBLEMS

One of the main components of stochastic assignment models is the route choice model solved with implicit or explicit path enumeration algorithms. Such models are used both for congested networks within equilibrium or dynamic models and for non-congested networks within static or pseudo-dynamic network loading models. This paper proposes a C-Logit model specification within a Dial algorithm structure for the implicit assignment of network flows. The model and its solution algorithm, called D-C-Logit, combine several positive features found in the literature for choice set generation and choices from a given choice set:• generation of a set of alternatives with a selective approach;• calculation of the path choice probability in a closed form;• simulation of the overlapping effect among alternative paths;• computation of just one tree for each origin avoiding explicit path enumeration.This paper has two main objectives: the proposition of a Dial-like algorithm to solve a C-Logit assignment model and application of the algorithm to different networks in order to demonstrate certain properties.

Safety of users in road evacuation: demand models

This paper proposes a demand model for the simulation of a transportation system in emergency conditions. The model is specified, calibrated and validated using data obtained from real experimentation in the urban area of Melito Porto Salvo in the province of Reggio Calabria (Italy), in relation to the research project SICURO, organized by LAST - Laboratory for Transport Systems Analysis and funded by the Calabria Regional Authority (EU Structural Funds 2000-2006). This paper analyses a formal demand model subdivided into the following sub-models: generation; modal split with distribution. All sub-models were validated using formal and informal tests.

STOCHASTIC USER EQUILIBRIUM ASSIGNMENT WITH EXPLICIT PATH ENUMERATION: COMPARISON OF MODELS AND ALGORITHMS

Abstract In this paper a preliminary analysis of alternative models for “feasible” path generation and choice is presented. In particular a k-shortest path multi-criteria model for path enumeration is explored and different choice models (Logit, recently proposed C-Logit and Probit) are tested by comparing SUE assignment link flows with counts on an urban road network. Flows are also compared for more traditional DUE and SUE Probit implicit path enumeration models. The results obtained show that a limited number (4-7) of paths generated with rather “simple” criteria give satisfactory results, SUE with explicit path enumeration is largely comparable with, and in some cases superior to, traditional implicit SUE and DUE models. Explicit path enumeration allow also the specification of more sophisticated non additive attributes in the utility function of route choice models. From the computational point of view the explicit path C-Logit and Probit SUE algorithms are from three to twenty times superior to the implicit Probit SUE assignment.

Safety of Users in Road Evacuation: Planning Internal Processes and Guidelines

In this paper a structured process to plan an urban system in emergency conditions is presented. The internal planning process is described with reference to planning dimensions and to a generic product-plan component. Guidelines for evacuation planning resulting from the SICURO project are presented, with a view to developing and testing an evacuation plan for an urban system in emergency conditions. Quantitative evaluations play an essential role in the guidelines.

Safety of Users in Road Evacuation: Modelling and DSS for LFA in the Planning Process

This paper presents the main modeling tools and Decision Support System (DSS) to support evacuation planning in urban system. Project Cycle Management (PCM), integrated with the Logical Framework Approach (LFA), is adopted to link the goals, outcomes, outputs with the strategies and inputs in the internal planning process. Main DSS to support PCM and LFA are presented.

Safety Of Users In Road Evacuation:Modelling And DSS For Demand

This paper describes how the SICURO research project was developed by the Laboratory for Transport Systems Analysis (LAST). The project includes demand analysis for transportation system simulation in emergency conditions. Herein, the authors propose the specification and calibration of generation and distribution with modal choice models. Using SP (Stated Preference) and RP (Revealed Preference) surveys. Software for demand model calibration and estimation is described, with some being used for the proposed model experimentation.

Safety of Users in Road Evacuation: General Methodology and Main Results

This paper presents the main results of the SICURO project. The objectives of the project are to: (1) calibrate, validate and test models and procedures to assess the effects of action to reduce risk in terms of exposure based on general real evacuations; (2) construct a prototype laboratory system of models for public administration where models and procedures are implemented; and (3) provide public administration with guidelines for planning and managing evacuation in an urban system under emergency conditions. The authors present the project, the methodology and the main general results obtained from experimentation and a detailed description is reported in the other paper of the session.

Evaluation Methods For Evacuation Planning

This paper will present the main evaluation methods to support evacuation planning in an urban system. In most cases, evaluation methods require knowledge of functions for relating variables that represent elements to evaluate. Nevertheless in real applications, functions for modeling evacuation are not always available. In these cases, sometimes it is necessary to use a method without the requirement for an explicit a priori determination of these functions. The authors propose two classes of methods to compare an evacuation plan, based on efficiency measures. An evacuation is represented by means of a virtual production process. An efficiency criterion is adopted to compare different evacuation process. Parametric and non parametric methods to estimate efficiency are compared. Input and output variables to represent an evacuation process are analyzed.

Urban Freight Models

The chapter discusses specific challenges and applications for modelling urban distribution. In fact, the analyses of urban freight transport traditionally focus only on restocking flows and usually neglect shopping flows. But the end-consumer choices in relation to type of purchasing undoubtedly impact on freight distribution flows and the end-consumer shopping choices depend on the commercial supply with respect to residence and on end-consumer behaviour, which in turn depends on some characteristics such as age, income, family dimension and lifestyle. Starting from literature, the paper reviews models for the urban freight movements, mapping the behaviour of the retailers and some aspects of the end consumers that generate freight movements in an urban context. Two macro-segments in the last miles of the freight supply chain are identified, with the retail outlet as final decoupling point: the segment upstream, between firms (push movements), and the segment downstream, between consumer and retailer (pull movements).