Workforce Development Resources

In this paper, a modelling framework to complete the recent scientific works on urban goods modelling is proposed. More precisely, we introduce a substitution procedure that estimates the number of trips and the corresponding travelled distances for shopping drive, home delivery and reception points' strategies. Moreover, an appraisal of scenarios is proposed in order to study how these three new forms of proximity delivery services impact on the overall urban goods movement distribution. Starting from four extreme situations, we introduce more realistic scenarios in order to find a suitable combination of delivery strategies. All the scenarios are simulated using the proposed framework, and the main traffic issues related to e-commerce distribution channel are discussed. The best realistic combination promotes the joint usage of home deliveries and proximity reception points and allows a reduction of about 13% of the road occupancy rates in urban areas.

The paper reports a modelling system to simulate goods movements at an urban scale. It allows joint analysis of choices made by end-consumers (assumed to be families) and retailers. These movements are examined at two levels: analysis of commodity flows, in terms of quantity, generated by the consumption of commodities; analysis of commodity flows, in terms of vehicles, due to restocking. The first level allows us to calculate the goods quantity flows due to consumption and restocking; the second level allows us to determine the service, vehicles used and target time, as well as the route chosen for restocking sales outlets in order to estimate vehicle flows on the urban/metropolitan transportation network. The modelling system is a multi-step model and considers a disaggregated approach for each decisional level.

Around the world, interest in urban and metropolitan goods movements is increasing since they account for a substantial share of traffic in urban/metropolitan areas. In this context, many city administrators have implemented measures to mitigate the negative effects of freight transport. Starting from an analysis of existing studies relative to freight policies implemented at urban scale, this paper proposes a general classification of measures adopted at an urban scale and an empirical analysis of obtainable results.

Many city public authorities have implemented measures to alleviate the negative effects of freight transport in urban areas, but these have often proved ineffective. The literature contains studies related to ex-post assessment of urban freight transport policies. This paper proposes a methodology for ex-ante assessment of their effects. The focus is the assessment of pollutant emissions. The application of the methodology to the inner urban area of Rome shows that an urban distribution centre can be more effective in reducing environmental externalities than policies based on vehicle fleet renewal.

This paper presents advancement on the calibration of a models system allowing us to estimate the goods attracted within urban and metropolitan areas. It is a component of a general modelling framework proposed by authors developed in order to support ex-ante assessment of city logistics measures. The primary characteristic of this general framework is the representation of interacting behavior of commodity consumers and commodity suppliers/shippers/retailers. In fact, this framework allows us to simulate goods movements at an urban scale combining urban passenger and commodity flows (commodity flows are generated in order to support a given need), and to investigate the existing relationships among end-consumers and other involved decision-makers (e.g. producers, wholesalers, retailers).

Freight demand models appear different from passenger models due to the distinction between the subject of the transport and the decision-makers as well as the multitude of agents involved in freight transport. In this work the authors applied a tour-based model to simulate freight distribution. The tour-based approach ably reproduces the choice structure of freight transport: this approach simulates the dependences existing between successive trips of the same distribution channel.

The method of assessment is as follows: analyze the generation of truck traffic, where different number of trucks are generated by the type of facility located within a freight village. A typical freight village model was created and was applied to six sites. The number of trucks generated by facilities is estimated using the truck trip rates from the ITE Trip Generation manual and relevant figures. To assess the impact of alternative land uses compared to freight village development, various scenarios were used for comparisons which include development of a business park, an amusement park and a regional park. The traffic impact of a freight village will then be compared to that of alternative developments.

The Clean Air Action Plan (CAAP), implemented by the Ports of Los Angeles and Long Beach in 2006, was an unprecedented effort to reduce air pollution emissions associated with port operations. We conduct a case study to understand why the ports developed the CAAP, how it was structured, and how it affected stakeholder relations. We identify those with the most influence in the international trade supply chain - 'dominant actors' - and hypothesize that they are the key participants in the CAAP development process and are least likely to be the subject of costly requirements or changes in operations. We find that the CAAP led to a restructuring of stakeholder relations, with new alliances formed between the ports and regulatory agencies and old alliances strained by what was perceived as a closed process utilized to develop the plan and as a lack of consideration of industry borne costs.

International trade has long been considered an important resource for local economic development in the United Stats (US). Local and state governments generally see ports as valued regional economic resources, and they have many policy tools to attract port-related trade, from favorable tax policies to infrastructure investment to direct subsidies. However, port-related trade also generates externalities that may affect local public support. Thus local and state governments may be faced with both promoting trade and addressing local concerns. At the same time, governance structures in the US have become more fragmented and decentralized, making it more difficult to manage such competing concerns. This paper examines programs to reduce landside congestion at two US west coast port complexes, Los Angeles-Long Beach and Seattle-Tacoma. The programs focused on grade separations to reduce conflicts between rail and highway traffic. Differences in outcomes are explained by both institutional and contextual factors. The ability to effectively address local externalities is emerging as a major factor in port competition on the US west coast.

Public transit policy is based on two objectives: to provide basic mobility for the transportation of disadvantaged, and to serve broader social and environmental goals by reducing car use in metropolitan areas of the United States. Planners, policy makers, and environmental advocates view better public transit as a means to achieve urban planning objectives. This article discusses the outcomes of the past four decades of transit policy. It begins with presenting a short history of transit policy to reveal the evolution of public transit's objectives. It then explores two areas of transit outcomes: impacts on low-income households and impacts on metropolitan spatial structure. Furthermore, it reveals how transit's dependence on public support creates barriers to achieving its societal goals. Finally, the article presents suggestions for designing more effective transit policies. Transit is critical to the economic well being of the cities, it is therefore important that public support for transit continues.

This paper examines the changes taking place in the way transportation policy and investment decisions are made. To provide an understanding of these changes, they are placed in the larger context of major trends in public-sector decision making: devolution, fragmentation, and privatization. The changes taking place in the transport sector are viewed as consistent with larger trends. The changes pose particular challenges in transportation because of its unique characteristics, and they have contributed to four problems: (a) preserving and enhancing system network benefits, (b) avoiding inefficient decisions, (c) solving transportation's externalities, and (d) ensuring accountability. The Alameda Corridor is used as an example of managing the new decision-making landscape. The paper closes with thoughts on improving the transportation decision-making process.

This paper conducts an international comparative analysis of relationships between car ownership, daily travel and urban form. Using travel diary data for the US and Great Britain, we estimate models of car ownership and daily travel distance. Both a structural model with daily travel conditional upon car ownership and a reduced form model for daily travel, excluding car ownership, are estimated. Model results are similar, and show that differences in travel are explained by (1) differences in demographics between the two countries; (2) lower household income in Great Britain; (3) country specific differences in costs of car ownership and use, transport supply and other factors we have not been able to control. We find that metropolitan size affects travel only in the largest metropolitan areas of the US. Daily travel distance is inversely related to local population density, but the effect is much stronger for the US than Great Britain. We conclude that higher transport costs in Great Britain promote economizing behavior, which in turns leads to more consumption of local goods and services and more use of alternative transport modes.

We present a method for estimating intra-metropolitan freight flows on a highway network. The work is part of a larger project aimed at developing an automated, integrated system for freight flow analysis and planning. To overcome the limitations of current estimation methods for commodity flows, we use reliable secondary sources, including small-area employment data, and derive estimates in a plausible way by means of a computational workflow. When available, we extract the data automatically from online sources, so that estimations can be continuously updated. Using widely available data sources allows for transferability. In this paper we provide an overview of our modeling approach and the major data sources used. We apply the model using data from the Los Angeles region, and compare our traffic assignment results with available screenline counts. Results are encouraging. Our approach should be easily applied to other metropolitan areas, allowing planners and policymakers to make more informed decisions by utilizing the most recent data from many sources and enhancing the ability to explore different scenarios.

This project links a newly developed method for estimating intra-metropolitan freight
flows with a widely used transportation planning software to demonstrate its feasibility
for sketch level regional transportation planning. We link the Argos planner, an
automated computational workflow, with the TransCAD transportation planning
software. The Argos planner was originally developed and tested with 2001 data for the
Los Angeles Region; we updated to 2007 data. The updated model results were
compared against the baseline model for the region. The linked system was used to test
three different policy scenarios: reduction in international trade, shift of freight from
truck to rail, and truck peak period pricing. The scenario results are plausible and
demonstrate the utility of the model for sketch level planning. A user-friendly graphical
interface was developed to allow easy use of Argos by practitioners. The linked model
would require additional development to be useful in professional practice. The
updating process is complex and requires expertise in both freight dynamics and
regional economic modeling. The modeling approach is unconventional, so would
require extensive training and technical assistance for use in public planning agencies.