Antonio Comi

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.

Urban freight transport and city logistics policies: Indications from Rome, Barcelona, and Santander

ABSTRACT This article compares the characteristics of urban freight transport in Rome, Barcelona, and Santander and the logistics measures being implemented in the three cities. The analysis is based on three similar surveys carried out in recent years involving interviews with retailers and transport operators. The main objective of this study is to evaluate the similarities and differences in terms of spatial patterns, current regulations, socioeconomic characteristics, commercial structures, freight demand characteristics, and current distribution patterns followed by different transport and logistics operators. The study shows that there are some different patterns of urban distribution that need to be taken into account when implementing city logistics measures in order to meet desired sustainability goals.

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).

Advanced public transport and intelligent transport systems: new modelling challenges

ABSTRACT Transit system ‘big data’ collecting and processing, and bidirectional communication between transit travellers and information centres are emerging as two factors that enhance the tools supporting short-term forecasting of network status for transit operations control and for traveller information. However, the current methodologies applied in these tools do not seem to have reached the level of research in the field of transit network modelling. Therefore, several methodological issues connected to the development of such tools are analysed in this paper. These issues concern application and development of real-time on-board load short-term forecasting methods, real-time best path advice, real-time transit assignment modelling, individual path choice modelling, and real-time updating and upgrading of demand and supply model parameters.

Urban freight transport policies in Rome: lessons learned and the road ahead

Given that few studies have investigated the effects of implementing city logistics measures, this paper focuses on actions implemented in the inner area of Rome in the last 10 years in order to improve both livability and freight distribution, providing insights into the effectiveness of such measures. The analysis covers the famous inner area of the city where the main tourist monuments are located and includes several pedestrianized shopping streets. Evaluation is based on data collected in 1999 and 2008 consisting of traffic counts and interviews with retailers and truck drivers. The implemented measures provided effective in abating through-traffic, in reducing the share of transport on own-account and in increasing the use of less polluting vehicles. Further, the increase in the number of stops per tour, in the average quantity delivered and hence in the average loading factor was revealed. Although all these changes improved the freight transport within the city, some critical issues remain and further measures have to be implemented.

Tactical and Operational City Logistics: Freight Vehicle Flow Modelling

This paper first classifies city logistics measures that city administrators can use to reduce the negative impacts of urban freight transport, in relation to planning (i.e. strategic and tactical/operational). The focus then shifts onto models developed to support the assessment of tactical and operational measures. The assessment procedures require the simulation of freight transport demand and hence the estimation of freight vehicle origin-destination (O-D) flows. These O-D flows can be obtained from the simulation of delivery tours. Therefore, the paper presents a system of models able to simulate delivery tours using an aggregate approach. Such models allow us to capture actors’ choices which can be influenced by tactical and operational measures. They were calibrated and tested using the surveys carried out in the inner area of Rome, where more than 500 truck drivers were interviewed. Some results of the validation of the models are also presented.

City logistics long-term planning: simulation of shopping mobility and goods restocking and related support systems

The growing necessity to improve city sustainability and liveability has pushed local administrators to look also at medium/long-term city logistics measures, such as land-use governance policies. In order to assess long-term scenarios, it is necessary to have models and methods able to take into account the effects on shopping mobility and goods restocking, generated by these classes of measures (e.g. relocation of shopping zones). Besides, we have to consider that modifications of shopping attitudes, deriving from changes of demographic and socio-economic characteristics of end consumers, can impact on purchasing behaviour and hence on restocking mobility. This paper discusses a number of issues related to the simulation of medium/long-term scenarios and presents a system of models that consider shopping mobility and restocking jointly. The presented shopping demand models, in combination with urban restocking models, are implemented within a simulation support system named City Logistics Analysis and Simulation Support System and are used to assess the effects on the freight restocking due to demographic and socio-economic variations including some hypotheses on new land-use development governance measures in a medium-size urban area. The main results confirm the modelling goodness and, at the same time, demonstrate that changes in demographic and socio-economic characteristics could cause relevant effects, in particular increasing car use in shopping mobility. The growing e-shopping could limit the negative effects of these changes, but the impacts of home deliveries have to be considered. The relocation of commercial and logistics centres, closer to the residential distribution, could drive a different restocking pattern with a consequent reduction in freight vehicle mobility. Anyway, this reduction is not very relevant and therefore further city logistics measures have to be implemented.

Estimation of target time distribution for agri-food products by road transport

This paper sets out to estimate the target time of trucks which transport agriculture and food products subject to commercial and production constraints. At the origin, carriers’ departure time is constrained by producer needs: the shipments are prepared through complex production chains, e.g. in the sector of perishable products these constraints are given by the end of the working day. At the destination there are constraints associated with the opening and closing time of markets and factories. In addition, there are some indifference time slices within which the freight transport is not subject to any penalty. Beginning with these considerations, an analysis of target time is developed, characterizing them by transported freight type and proposing models to investigate their time distribution.

An aggregate transport demand model for import and export flow simulation

This paper presents a system of models for the estimation of international (import/export) freight flows through a partial share approach. It allows us to simulate attraction, production, distribution and modal split for the estimation of modal Origin-Destination matrices in quantities. Aiming at predicting long term effects for strategic planning, the modelling system has been specified through easy-to-capture variables represented by level-of-service attributes and aggregate socio-economic variables. The calibration was carried out by using a set of available data in Italy that allowed us to consider import/export flows for different freight types given by the aggregation of classes provided by European NST/R classifications.

A mesoscopic transit assignment model including real-time predictive information on crowding

ABSTRACT This article presents a mesoscopic transit assignment model suitable for real-time prediction of on-board passenger numbers in transit networks with real-time individual predictive information on travel time components and also including on-board crowding. The path choice modeling framework is based on the reproduction of a travel strategy using random utility models that simulate both choices of departure time at origin and first access stop, and en-route choices of vehicle to board at stops. Such choices are based on attributes anticipated through a learning mechanism, which considers previous experiences and provides real-time predictive information. Within-day dynamic network loading considers vehicle capacity constraints, which allows the explicit modeling of fail-to-board events. Finally, results of an application on a real-size test network show the ability of the model to capture effects of providing individual predicted information on vehicle crowding.