Alternative Approaches to Modeling the Travel-Demand Impacts of Smart Growth

Four-step travel demand forecasting models were never meant to estimate the travel impacts of neighborhood-level smart growth initiatives like transit villages, but rather to guide regional highway and transit investments. While progress has been made in enhancing large-scale models, some analysts have turned to post-processing and direct models to reduce modeling time and cost, and to better capture the travel impacts of neighborhood-scale land use strategies. This paper presents examples of direct or off-line modeling of rail and transit-oriented land use proposals for greater Charlotte, the San Francisco Bay Area exurbs, and south St. Louis County. These alternative approaches provided a useful platform for scenario testing, and their results revealed that concentrating development near rail stations produced an appreciable ridership bonus. These alternative models are appropriate as sketch-planning supplements to, not substitutes for, traditional four-step models.     

Influence of Demand Uncertainty and Correlations on Traffic Predictions and Decisions

Abstract: Decisions to improve a regional transportation network are often based on predictions of future link flows that assume future travel demand is a deterministic matrix. Despite broad awareness of the uncertainties inherent in forecasts, rarely are uncertainties considered explicitly within the methodological framework due at least in part to a lack of knowledge as to how uncertainties affect the optimality of decisions. This article seeks to address this issue by presenting a new method for evaluating future travel demand uncertainty and finding an efficient technique for generating multiple realizations of demand. The proposed method employs Hypersphere Decomposition, Cholesky Decomposition, and user equilibrium traffic assignment. Numerical results suggest that neglecting correlations between the future demands of travel zone pairs can lead to improvement decisions that are less robust and could frequently rank improvements improperly. Of the six sampling techniques employed, Antithetic sampling generated travel demand realizations with the least relative bias and error.     

Estimated apparatus speeds by street type in Chicago,Illinois

The Chicago Fire Department conducted road tests to measure fire apparatus speeds in various areas of the city for the purpose of estimating input to a computer-simulated fire apparatus transportation network. This network was then processed by a minimum path algorithm, and the estimated speeds were used along each path to compute emergency response travel times. These emergency response travel times were used for purposes such as site planning, deployment evaluation, and analyses of citywide fire protection coverage. A review of the literature provided insights explaining apparatus speeds, but little in the way of practical information for purposes of network travel time analysis. This paper describes the Chicago road test methodology, and shares the results of the study.     

芝加哥工业保护规划对珠三角城市工业用地区划探索的启示

20世纪80~90年代芝加哥市政府为保护工业、维持城市活力,以计划制造区规划为开端,在区划、基础设施、财税等不同方面推行了一系列工业用地的管理保护措施。由此带来制造业回流与先进制造业发展,芝加哥政府在此基础上有力推动了工业走廊现代化运动。近年来,深圳、广州、惠州等珠三角城市相继颁布工业控制线等管控现有工业用地转换的工业区块规划,成为国土空间规划编制的重要基础。通过梳理芝加哥工业保护规划制定和发展的历程,总结芝加哥在土地利用基础上的一系列制造业保护措施,为我国城市工业区块规划提供借鉴及启发。     

Dynamic forecasting of travel demand,residential location and land development

TheChicago Area Transportation/Land-Use Analysis System (CATLAS) is a large scale urban simulation model which synthesizes location rent analysis from urban economics with travel demand analysis from transportation planning. This paper describes the theoretical formulation, empirical estimation and policy application of CATLAS to the evaluation of CBD-oriented rapid transit projects in Chicago.     

Report on Project East River

A traffic model was developed by the Chicago Area Transportation Study for predicting urban traffic volumes. The research conducted by CATS indicates that a combination of the gravity model and a linear programming technique provides a sound method for forecasting. Linear programming is one of the newest techniques in the industrial field. It can be applied to the city planning field to indicate expected travel patterns that would result. Tests reveal that it is a satisfactory and reliable procedure for forecasting traffic.     

Increasing Access to Transit: Localized Mobile Information

While several studies note the challenges that people with disabilities face when using public transit, little work has investigated how mobile transit information apps affect accessibility. To address this gap, we recruited transit riders who are blind, who have low vision, who use mobility devices, and who have no disabilities. We asked them to use a transit information app, Tiramisu, for 21 days during their regular travel. We observed participants struggling with a number of barriers that had previously been reported. However, the localized transit information also removed barriers to travel; we observed participants engaging in less preplanning and more opportunistic travel. We also identified new opportunities to improve transit use through mobile information.     

CLOSING AND OPENING SCHOOLS: THE ASSOCIATION BETWEEN NEIGHBORHOOD CHARACTERISTICS AND THE LOCATION OF NEW EDUCATIONAL OPPORTUNITIES IN A LARGE URBAN DISTRICT

ABSTRACT: New charter schools can potentially provide disenfranchised students with enhanced academic opportunities while simultaneously serving as neighborhood anchors that reinforce neighborhood socioeconomic growth. However, for both of these arguments to be true, charter schools would have to replace low‐performing public schools in currently disadvantaged, but revitalizing, neighborhoods. Using data from the Chicago Public Schools, the Common Core, and the Census, we examine the neighborhood and school‐level factors that account for where elementary schools closed and opened in Chicago during the late 1990s and 2000s. We find that schools in disadvantaged neighborhoods were more likely to close, but only because these were also underperforming and under‐enrolled schools. After controlling for educational demand, new schools were more likely to open in neighborhoods that showed signs of socioeconomic revitalization and declining proportions of white residents.     

芝加哥的滨水区建设

根据作者对芝加哥湖滨地区和沿芝加哥河两岸的调查,指出有预见性的城市规划在城市发展和建设中的巨大意义,像1909年的芝加哥规划,1972年的湖滨区规划和1974年的滨河区规划等,在评价城市美化运动的同时,揭示了将湖滨地区保留为面向公众的,城市开敞空间的意义。     

What Is a Forecast for?

Abstract

Problem, research strategy, and findings: The forecasts transit agencies submit in support of applications for federal New Starts funding have historically overestimated ridership, as have ridership forecasts for rail projects in several countries and contexts. Forecast accuracy for New Starts projects has improved over time. Understanding the motivations of forecasters to produce accurate or biased forecasts can help forecast users determine whether to trust new forecasts. For this study I interviewed 13 transit professionals who have helped prepare or evaluate applications for federal New Starts funds. This sample includes interviewees who have had varying levels of involvement in all 82 New Starts projects that opened between 1976 and 2016. I recruited interviewees through a snowball sampling method; my interviews focus on the interviewees’ perspectives on how New Starts project evaluation and ridership forecasting has changed over time. Interview results suggest that ridership forecasters’ motivations to produce accurate forecasts may have increased with increased transparency, increased influence on local decision making, and decreased influence on external (federal) funding.

Takeaway for practice: Planners can evaluate the likely trustworthiness of forecasts based on transparency, internal influence, and external influence. If forecast users cannot easily determine a forecast’s key inputs and assumptions, if the forecaster has been tasked with producing a forecast to justify a predetermined action, and if an unfavorable forecast would circumvent decisions by the forecaster’s immediate client, forecasts should viewed with skepticism. Planners should seek to alter conditions that may create these conflicts of interest. Forecasters seem to be willing and able to improve forecast accuracy when the demand for accurate forecasts increases.     

Polycentrism as a sustainable development strategy: empirical analysis from the state of Maryland

We present in this paper an analysis of economic centers and their role in shaping employment development patterns and travel behavior in the state of Maryland. We begin by identifying 23 economic centers in the Baltimore-Washington region. We then examine these centers first in their role as centers of economic activity and then in their role as nodes in the state’s transportation system. Finally, we identify the commute sheds of each center, for multiple modes of travel and travel times, and examine jobs–housing balance within these various commute sheds. We find that Maryland’s economic centers not only promote agglomerative economies and thus facilitate economic growth; they also generate a disproportionate number of trips and promote transit ridership. These results provide empirical support for policies that promote polycentric urban development, and especially policies that promote polycentric employment development. Further, they suggest that polycentrism as a sustainable development strategy requires careful coordination of regional transportation systems designed to balance jobs and housing within a center’s transit commute shed. Based on these findings we recommend that the Maryland state development plan, and regional sustainable communities plans across the nation, encourage the concentration of employment within economic centers and encourage housing development within the transit commute sheds of those centers.     

Slow Train Coming: The New Zealand State Changes its Mind about Auckland Transit, 1949–56

Two recent articles have described an ‘Americanisation’ of transport policy in Auckland, New Zealand, characterised by the successful advocacy of motorways at the expense of rail. Arrested development of rail transit in Auckland presents a striking contrast to Wellington, New Zealand, where suburban rail is as well developed relative to population as in Perth (WA). Wellington's suburban rail was installed as part of a state-led development planning programme. By the late 1940s this template was intended for extension to Christchurch and to Auckland, then undergoing rapid growth. Following a change of government in 1949 development planning ceased and a state highway fund was established to fund urban motorways instead. The principal conclusion is that state support for development planning along transit corridors may be a prerequisite for successful urban transit development.     

Financing Rail Rapid Transit System: A Comparison Between Chicago and Shanghai

Detailed financial information of a rail rapid line project is often unavailable to the general public until a project has been completed for a couple of years and even for decades. This is especially true in the Chinese context. Based on available information, this paper compares four aspects of the financing of two rail rapid lines that were built almost simultaneously in Shanghai of China and Chicago of the US. The author finds: first, the central governments had the greatest impact on the capital investment in both lines; second, the formation of transit and financial plans in two cities both involved complicated political processes which were shaped by certain political figures and unforeseeable events; third, in the longer term, it was more expensive to maintain a rail rapid line than to build a new line in both countries; and finally, mainly depending on foreign loans and bonds, Shanghai faced greater challenge in offsetting the financial deficit. But this situation was improved as the Shanghai rail rapid system expanded and matured.     

Housing location choices of the poor: does access to jobs matter?

Abstract

This research investigates whether access to jobs affects poor households’ residential location choices using data from individual households in the Chicago Metropolitan Area. Our results, based on discrete choice models, show that the effects of job accessibility on household location choices are contingent upon households’ automobile ownership and employment status. Places with higher job accessibility by public transit mode are more likely to attract poor households that do not own cars but have at least one employed worker or one labour force participant, while job accessibility by automobile travel mode has no positive effect on the location choices of poor households who own automobiles. The results stress the importance of job accessibility for those poor households with limited transportation mobility but strong needs for access to jobs.     

Reliability‐Based Transit Assignment for Congested Stochastic Transit Networks

Abstract: This article proposes a nonlinear complementarity problem (NCP) formulation for the risk‐aversive stochastic transit assignment problem in which in‐vehicle travel time, waiting time, capacity, and the effect of congestion are considered as stochastic variables simultaneously and both their means and variances are incorporated into the formulation. A new congestion model is developed and captured in the proposed NCP formulation to account for different effects of on‐board passengers and passengers waiting at stops. A reliability‐based user equilibrium condition is also defined based on the proposed generalized concept of travel time budget referred to as effective travel cost, and is captured in the formulation. A column generation based algorithm is proposed to solve the NCP formulation. A survey was conducted to validate that the degree of risk aversion of transit passengers affects their route choices. Numerical studies were performed to demonstrate the problem and the effectiveness of the proposed algorithm. The results obtained show that underestimating the congestion effect and ignoring the risk aversion behavior can overestimate the patronage of transit service, which have profound implications on the profit of the operators involved and the development of transit network design models.     

The impact of residential neighborhood type on travel behavior: A structural equations modeling approach

Using a system of structural equations, this paper empirically examines the relationship of residential neighborhood type to travel behavior, incorporating attitudinal, lifestyle, and demographic variables. Data on these variables were collected from residents of five neighborhoods in the San Francisco Bay Area in 1993 (final N=515), including “traditional” and “suburban” as well as mixtures of those two extremes. A conceptual model of the interrelationships among the key variables of interest was operationalized with a nine-equation structural model system. The nine endogenous variables included two measures of residential location type, three measures of travel demand, three attitudinal measures, and one measure of job location.  In terms of both direct and total effects, attitudinal and lifestyle variables had the greatest impact on travel demand among all the explanatory variables. By contrast, residential location type had little impact on travel behavior. This is perhaps the strongest evidence to date supporting the speculation that the association commonly observed between land use configuration and travel patterns is not one of direct causality, but due primarily to correlations of each of those variables with others. In particular, the results suggest that when attitudinal, lifestyle, and sociodemographic variables are accounted for, neighborhood type has little influence on travel behavior. Received: March 2001/Accepted: October 2001     

THE DILEMMAS OF BUILDING A PROGRESSIVE URBAN COALITION: The Linked Development Debate in Chicago

ABSTRACT: In 1983 Chicago elected its first black mayor, Harold Washington. During Washington's first term of office, his administration not only reordered municipal priorities in such a fashion as to benefit his core, minority voting constituency, but also defined a municipal agenda emphasizing greater attention to neighborhood needs and more open government. In 1984 an important neighborhood coalition, the Save Our Neighborhoods/Save Our City Coalition (SON/SOC), proposed a linked development policy to tap downtown investment for neighborhood projects. Although SON/SOC's proposal was compatible with the Washington neighborhood agenda, this mainly white organization and the Washington administration experienced considerable difficulty in forging a mutually acceptable proposal The linked development debate in Chicago demonstrates the salience of race, class-cultural factors, and alternative approaches to neighborhood mobilization as barriers to the development of progressive coalitions in city politics.     

From the Editors

Problem: Reducing gasoline consumption could sharply curtail greenhouse gas emissions. Ongoing research seeks to document factors associated with green travel behavior, like walking and transit use.

Purpose: We seek to determine whether green beliefs and values are associated with green travel behavior. We measure whether residents of communities with environmentalist attributes drive less, consume less gasoline, and are more likely to commute by private vehicle. We explore several channels through which green beliefs and values may affect travel behavior and vice versa.

Methods: We drew our demographic, transportation, and built environment data from the 2000 Census of Population and Housing including the Public Use Microdata Sample and the 2001 National Household Travel Survey, and constructed our indicators of green ideology using voting records, political party membership, and data on hybrid auto ownership. We estimated ordinary least squares regression and linear probability models using both individual households and small areas as units of analysis.

Results and conclusions: We find green ideology is associated with green travel behavior. People with green values are more likely than others to be located in communities with high population densities and proximity to city centers and rail transit stations, which are attributes conducive to environmentally friendly travel. We also find that residents of green communities engage in more sustainable travel than residents of other communities, even controlling for demographics and the effects of the built environment. Green ideology may cause green travel behavior because greens derive utility from conservation or because greens locate in, or create, areas with characteristics that promote sustainable travel. We also discuss the possibility that green travel behavior may cause green beliefs.

Takeaway for practice: If greens self-select into dense, central, and transit-friendly areas, the demand for these characteristics may rise if green consciousness does. Alternatively, if these characteristics cause green consciousness, their promotion promises to increase green behavior. The implications of our finding that residents of green communities engage in more sustainable travel patterns than others depends on the causal mechanism at work. If greens conserve because they derive utility from it, then environmental education and persuasion may bring about more sustainable travel. Alternatively, if green travel behavior causes green beliefs, it is possible that attracting more travelers to alternate modes and reducing vehicle miles traveled may increase environmental consciousness, which may in turn promote other types of pro-environment behavior.

Research support: None.     

空间转型和经济转型——二战后芝加哥中心区再开发

芝加哥在战后成功地实现了从传统制造业为中心向现代服务业为中心的经济转型，被认为是美国多元化城市经济的典范。本文从公共政策和城市规划的角度，对芝加哥中心区在战后50年的空间和土地利用变化进行回顾和分析，反映了中心区的复兴过程和城市的经济转型过程，并介绍了2020年芝加哥中心区规划。笔者认为，在芝加哥战后经济转型的过程中体现了城市政府对不同经济发展战略的选择，经济发展的长期目标是创造就业和提高全体居民的生活质量；在经济转型的过程中，城市规划应在土地利用、空间资源分配、社会公平和公正方面发挥作用，为多元化的经济结构创造多样化、高质量的城市空间，而不仅仅关注于物质建设领域。     

公路工程管理完善方法探究

人民经济水平随着我国经济的发展得到了显著提升，人们的出行需求也日益增长。为了能够保障人们的出行安全，就对公路工程建设提出了更高的要求，公路工程管理就显得相当重要。本文主要就公路工程管理的完善问题进行了探讨。