Iván Sánchez-Díaz

Estimated Generation of Freight Trips Based on Land Use

The effects of land use and business size (quantified as number of employees) on freight trip generation were analyzed. Standard trip generation rates, ordinary least squares, and multiple classification analysis were applied to a New York City data set. Three land use classification codes—the City of New York zoning resolution (NYCZR), the Land-Based Classification Standards (LBCS), and the Institute of Transportation Engineers (ITE) manual—were used. The authors developed models for NYCZR and function and activity of LBCS and used the ITE manuals trip rates. Root mean square error analysis was used to compare the performance of these models. It was found that models for NYCZR and LBCS land use classification codes provide better alternatives to ITE trip rates because they give more accurate estimates of freight trip attraction, cover a wider range of land use classifications, and are exclusively for freight trip attraction.

Transferability of Freight Trip Generation Models

The main objectives of this paper are to assess and define ways to enhance the transferability of freight trip generation (FTG) models. After the key premises that should guide the development of FTG models have been presented, the paper assesses transferability in two ways. The first is through analyses of how well representative FTG models are able to estimate the actual FTG for a number of external validation cases. The second is through FTG econometric models that assess the statistical significance of binary variables that represent specific geographic locations. In addition, the paper introduces and assesses the accuracy of a synthetic correction procedure that is intended to improve the transfer-ability and quality of the estimates provided by the FTG rates available in the literature. The results show that the models developed as part of the National Cooperative Freight Research Programs Project 25, Freight Trip Generation and Land Use, have better prediction capabilities than the models included in other compilations. In addition, the synthetic correction procedures improve transferability, and no locational effects are present in the test data.

Freight Generation and Freight Trip Generation Models

This chapter provides an overview of freight generation (FG) and freight trip generation (FTG) modeling for urban areas. To this effect, the authors discuss the literature, propose a logistical interpretation of FG and FTG, summarize the key factors for effective FG and FTG modeling, and describes the FTG models developed for New York City. The chapter concludes with statements of conclusions.

Improving Freight System Performance in Metropolitan Areas: A Planning Guide

This report provides a regional public planning guide that identifies potential strategies and practical solutions for public and private stakeholders to improve freight movement system performance in diverse metropolitan areas. The Guide is intended to serve as a comprehensive reference for all portions of a metropolitan area, from the urban core to more suburban and exurban areas (urban fringe). The Guide includes an Initiative Selector tool to aid in the selection of possible alternatives for various problems, and Freight Trip Generation (FTG) software that planners can use to identify main locations where freight is an issue based on freight trips produced and attracted. Links to access the Initiative Selector and FTG software appear in this report. The report is divided into three sections: Section 1: Urban Freight Transportation Decision-Making Process; Section 2: Overview of Public-Sector Initiatives; and Section 3: Case Studies.

Freight Trip Generation and Land Use

This report provides a comprehensive discussion of how the freight system, and specifically freight trip generation and land use, relate. The report consolidates available freight trip generation models in an electronic database to assist practitioners interested in using these models; identifies the most appropriate approaches to develop and apply freight trip generation models; and estimates establishment-level freight trip generation models in a number of case studies. The case studies confirm the superiority of economic classification systems over standard land use classification systems as the foundation for estimating freight trip generation.

Shifting Urban Freight Deliveries to the Off-Peak Hours: A Review of Theory and Practice

ABSTRACT This paper presents a comprehensive review of the literature on off-peak hour deliveries (OPHD). The review identifies different approaches and policy levers used in the past, such as the laissez-faire approach, a road pricing approach, an incentives approach, and a regulatory approach. The paper also identifies different delivery reception schemes discussed in the literature. The authors complement the theory with a synthesis of pilot tests and the analysis of a set of interviews with practitioners (from the public sector and other organisations) in charge of OPHD programmes. The results from this review show the potential benefits that these programmes could bring about, the challenges faced in the early stages – along with potential solutions – and the significant progress that has been made in this domain in the last decade. According to the review, the results from the pilot tests tend to be positive, suggesting the importance of these programmes to reach more efficient and sustainable transportation systems.

Identifying Freight Intermediaries. Implications for Modeling of Freight Trip Generation

This study discusses freight trip generation of pure receiver establishments, establishments that only receive goods, and freight intermediaries, establishments that both receive and ship goods. In addition, freight trip attraction and freight trip production patterns of establishments in different industry sectors were compared by using freight generation models. The analyses indicated important differences between production and attraction between establishments across and within industry segments and between pure receivers and intermediaries. As a result, econometric models (discrete and discrete-continuous models) were estimated to identify intermediary establishments. External data were used to validate the estimated models. The analyses and models could be used to improve modeling of freight trip generation.

The New York City Off-Hour Delivery Program: A Business and Community-Friendly Sustainability Program

The New York City Off-Hour Delivery (NYC OHD) program is the work of a private-public-academic partnership—a collaborative effort of leading private-sector groups and companies, public-sector agencies led by the New York City Department of Transportation, and research partners led by Rensselaer Polytechnic Institute. The efforts of this partnership have induced more than 400 commercial establishments in NYC to accept OHD without supervision. The economic benefits are considerable: the carriers have reduced operational costs and parking fines by 45 percent; the receivers enjoy more reliable deliveries, enabling them to reduce inventory levels; the truck drivers have less stress, shorter work hours, and easier deliveries and parking; the delivery trucks produce 55–67 percent less emissions than they would during regular-hour deliveries, for a net reduction of 2.5 million tons of CO2 per year; and citizens’ quality of life increases as a result of reduced conflicts between delivery trucks, cars, bicycles, an...

Exploring Carriers Perceptions about City Logistics Initiatives

An attitudinal study conducted in Brasilia, the Federal District of Brazil, is presented. Carrier managers were asked about their operational characteristics, problems faced on urban freight distribution, and a set of city logistics initiatives (CLI). The respondents were also asked about external factors affecting the implementation of these initiatives. The methodology used a Likert-scale scheme to evaluate the responses and to implement nonparametric tests to explore relationships between opinions and carriers’ attributes. The results show that finding parking is considered the main obstacle for efficient urban distribution, followed by traffic congestion and long delivery times. In regard to the CLI, vehicle parking reservation systems and off-hour deliveries are supported by all the carriers interviewed. Local pickup points and unassisted deliveries produce the highest opposition, mainly because these CLI are suitable for specific types of customers and commodities. The results shed light on the factors influencing the implementation of CLI from the point of view of carriers and suggest segments with common operational attributes that could be targeted for each initiative.

An investigation of the effects of critical infrastructure on urban mobility in the city of Medellín

Critical infrastructure refers to the type of facilities, services, and installations (e.g., transportation, communication, energy systems) that are essential for the functioning of a community, city or country. This paper describes the findings of the research conducted to identify the transportation network critical facilities (road links) and their impacts on urban mobility for the city of Medellin, the second largest city in Colombia. This paper analyses the negative effects on travel time when a facility is disrupted or the capacity is suddenly reduced (e.g., accident, natural or manmade disaster, dedicated bike-route, maintenance, and construction). Criticality is identified following two methodologies: 1) comparing the travel time of the network users solving the user equilibrium (UE) traffic assignment problem between the base case and the disrupted network; 2) assessing the impact of the disrupted facility on the path travel times between affected origin-destinations zones.