Doescher, Mark P.; Lee, Chanam; Saelens, Brian E.; Lee, Chunkuen; Berke, Ethan M.; Adachi-mejia, Anna M.; Patterson, Davis G.; Moudon, Anne Vernez. (2017). Utilitarian and Recreational Walking Among Spanish- and English-Speaking Latino Adults in Micropolitan US Towns. Journal Of Immigrant & Minority Health, 19(2), 237 – 245.
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Abstract
Walking among Latinos in US Micropolitan towns may vary by language spoken. In 2011-2012, we collected telephone survey and built environment (BE) data from adults in six towns located within micropolitan counties from two states with sizable Latino populations. We performed mixed-effects logistic regression modeling to examine relationships between ethnicity-language group [Spanish-speaking Latinos (SSLs); English-speaking Latinos (ESLs); and English-speaking non-Latinos (ENLs)] and utilitarian walking and recreational walking, accounting for socio-demographic, lifestyle and BE characteristics. Low-income SSLs reported higher amounts of utilitarian walking than ENLs (p = 0.007), but utilitarian walking in this group decreased as income increased. SSLs reported lower amounts of recreational walking than ENLs (p = 0.004). ESL-ENL differences were not significant. We identified no statistically significant interactions between ethnicity-language group and BE characteristics. Approaches to increase walking in micropolitan towns with sizable SSL populations may need to account for this group's differences in walking behaviors.
Keywords
Walking; Confidence Intervals; Ecology; Ethnic Groups; Hispanic Americans; Income; Language & Languages; Metropolitan Areas; Population; Public Health; Recreation; Rural Conditions; White People; Logistic Regression Analysis; Socioeconomic Factors; Social Context; Body Mass Index; Acquisition Of Data; Physical Activity; Data Analysis Software; Odds Ratio; United States; Environment Design; Ethnicity; Rural Populations; Physical-activity; Built Environment; United-states; Postmenopausal Women; Acculturation; Risk; Transportation; Mortality; Health; Associations; Studies; Demographic Aspects; Telephone Surveys; Minority & Ethnic Groups; Physical Fitness; Low Income Groups; Urban Environments; Demographics; Language; Accounting; Statistical Analysis; Urban Areas; Towns; Populations; Adults; Lifestyles; Latin American Cultural Groups; Sociodemographics; Landscape Architecture; Population Growth; Pediatrics; Leisure; Health Care; Noncitizens; Preventive Medicine; United States--us
Nnaji, Chukwuma; Lee, Hyun Woo; Karakhan, Ali; Gambatese, John. (2018). Developing a Decision-Making Framework to Select Safety Technologies for Highway Construction. Journal Of Construction Engineering And Management, 144(4).
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Abstract
Highway construction has consistently reported relatively high fatality rates largely because of the considerable exposure of workers to live traffic. To address this anomaly, traffic control planners are tasked with making decisions geared toward reducing hazardous situations caused by transiting vehicles and construction equipment. The growing application of technologies to enhance worker safety should be considered during the traffic control planning process. In certain cases, decisions such as choosing among technology options are made using experiential individual knowledge without the application of scientific and systematic decision-making methods. Use of experience-based decision making in this context is largely the result of sparse literature on scientific methods of selecting between alternatives in highway construction work zones. By applying the Choosing by Advantages (CBA) decision-making method, a process that achieves sound and effective decisions, the current study aims to fill the gap in practice by proposing a decision-making framework that could enhance the value-cost selection process of safety technologies in highway construction work zones. A situation that applied work zone intrusion alert technologies (WZIATs) was selected as a case study. Using a focus group session and case projects as an evaluation study process, the proposed framework based on the CBA decision-making process was applied to evaluate three WZIATs. Findings from the current study will benefit safety professionals and practitioners by providing a step-by-step approach to make sound decisions that can enhance the level of safety in highway construction work zones.
Keywords
Construction Equipment; Decision Making; Occupational Safety; Project Management; Road Building; Effective Decisions; Decision-making Framework; Value-cost Selection Process; Highway Construction Work Zones; Work Zone Intrusion Alert Technologies; Cba Decision-making Process; Sound Decisions; Traffic Control Planners; Worker Safety; Traffic Control Planning Process; Technology Options; Scientific Decision-making Methods; Systematic Decision-making Methods; Experience-based Decision Making; Advantages Decision-making Method; Safety Technologies; Knowledge; Signs
Guan, Jinping; Zhang, Kai; Shen, Qing; He, Ying. (2020). Dynamic Modal Accessibility Gap: Measurement and Application Using Travel Routes Data. Transportation Research: Part D, 81.
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Abstract
Accessibility is a key concept in transportation research and an important indicator of people's quality of life. With the development of big data analytics, dynamic accessibility that captures the temporal variations of accessibility becomes an important research focus. Few prior studies focus on comparative measures of dynamic accessibility to Points of Interest (POIs) by alternative travel modes. To fill this research gap, we propose a new index called dynamic modal accessibility gap (DMAG), which draws upon available data on residents' real travel routes using different travel modes, as well as the data on POIs. We study the DMAG in the real-travel covered area, assuming POIs are only useful if it is within someone's real-travel covered area. We then apply this DMAG methodology to Shanghai's central city and peripheral area. In both cases, we measure the accessibility for public and private travel modes. As an example, one-week taxi GPS and metro smart card data, and POIs data are used to generate the DMAG index for 30-minute and 60-minute trip durations for weekdays and holidays. Results show that DMAG can reflect the pattern of temporal variations. The proposed DMAG analytical framework, which can be applied at both the user and the system levels, can support urban and transportation planning, and promote social equity and livability.
Keywords
Air Travel; Choice Of Transportation; Urban Transportation; Transportation Planning; Urban Planning; Smart Cards; Inner Cities; Route Choice; Shanghai (china); Dynamic Accessibility; Modal Accessibility Gap (mag); Points Of Interest (pois); Public And Private Travel Modes; Temporal Variations; Scale Residential Areas; Transport; Time; Dimensions; Employment; Indicator; Choice; Boston; Car
Dunn, Peter T. (2021). Autonomous People: Identity, Agency, and Automated Driving. Journal Of Urban Technology, 28(3-4), 25 – 44.
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Abstract
The prevailing discourse on autonomous vehicles (AVs) has not yet developed a sophisticated conceptualization of autonomy and has given insufficient attention to the autonomy of people. In response, this article shifts our attention away from the AV's autonomy and towards that of its user. Autonomy is conceived here as the socially and materially situated capacity of an individual to identify and act on one's own values and desires, a capacity that is desirable for collective political life. This definition is drawn selectively from a survey of thought illustrating the richness of this concept. I then examine how studies of transportation have already made use of certain themes of autonomy in understanding mobility practices beyond dominant utilitarian models. This sets up an examination of AVs, where the existing literature tends to use a narrow conceptualization of autonomy. I then briefly examine two examples of unsettled questions in AV development, discretionary user controls and shared ride systems, in light of autonomy. The goal of this article is both to show how autonomy can be productive in understanding mobility practices, and to argue for personal autonomy as a normative value worth pursuing in the technical, political, and social development of automated mobility systems.
Keywords
Car Use; Vehicles; Travel; Accidents; Policy; Autonomy; Agency; Autonomous Vehicles; Mobility
Grengs, Joe; Levine, Jonathan; Shen, Qing; Shen, Qingyun. (2010). Intermetropolitan Comparison of Transportation Accessibility: Sorting Out Mobility and Proximity in San Francisco And Washington, DC. Journal Of Planning Education And Research, 29(4), 427 – 443.
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Abstract
Both mobility and proximity influence transportation accessibility, but they exist in tension with each other. To understand the region-level trade-off between mobility and proximity requires intermetropolitan comparisons of accessibility. With a focus on the two metropolitan cases of San Francisco and Washington, D.C., we first describe a method for comparing regional accessibility and then explain a method that separates out the effects of mobility and proximity on regional accessibility. We find that the San Francisco region enjoys an accessibility advantage over Washington largely because of faster highway speeds but that central Washington offers an advantage in proximity.
Keywords
Spatial Interaction; Employment; Location; Access; Sprawl; Land Use; Methods; Nonwork Travel; Transportation; Urban Form; Regional Accessibility
Yang, Jiawen; Shen, Qing; Shen, Jinzhen; He, Canfei. (2012). Transport Impacts of Clustered Development in Beijing: Compact Development Versus Overconcentration. Urban Studies, 49(6), 1315 – 1331.
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Abstract
This research aims to inform the compact city discussion with a case study of Beijing, where urban planning has emphasised clustered suburban development in the past half-century. It uses three decades of census data to describe Beijing's spatial development trajectory and a household survey to assess its transport impacts. The research reveals an overconcentration of urban activities as a result of the featureless expansion of the central built-up area and the absorption of the suburban clusters; and, a lengthened commuting time stemming from the observed spatial development pattern. Beijing's experience adds to the existing literature by informing the search for good city forms in urban areas of high density. It is essential to differentiate compact development from overconcentration when combating sprawling development. Developing and maintaining suburban nodal characteristics around public transit can reduce travel in high-density urban areas.
Keywords
Jobs-housing Balance; Commuting Patterns; Urban; Growth; City; Towns
Stewart, Orion Theodore; Moudon, Anne Vernez. (2014). Using the Built Environment to Oversample Walk, Transit, and Bicycle Travel. Transportation Research: Part D, 32, 15 – 23.
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Abstract
Characteristics of the built environment (BE) have been associated with walk, transit, and bicycle travel. These BE characteristics can be used by transportation researchers to oversample households from areas where walk, transit, or bicycle travel is more likely, resulting in more observations of these uncommon travel behaviors. Little guidance, however, is available on the effectiveness of such built environment oversampling strategies. This article presents measures that can be used to assess the effectiveness of BE oversampling strategies and inform future efforts to oversample households with uncommon travel behaviors. The measures are sensitivity and specificity, positive likelihood ratio (LR+), and positive predictive value (PPV). To illustrate these measures, they were calculated for 10 BE-defined oversampling strata applied post-hoc to a Seattle area household travel survey. Strata with an average block size of <10 acres within a 1/4 mile of household residences held the single greatest potential for oversampling households that walk, use transit, and/or bicycle. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords
Cycling; Transportation; Observation (scientific Method); Strategic Planning; Public Transit; Land Use; Bicycle; Household Travel Survey; Non-motorized Travel; Sampling; Screening Tests; Transit; Walk; Land-use; North-america; Renaissance; Policies; Choice; Trends
Fantilli, Alessandro P.; Nemati, Kamran M.; Chiaia, Bernardino. (2016). Efficiency Index for Fiber-Reinforced Concrete Lining at Ultimate Limit State. Sustainable And Resilient Infrastructure, 1(1-2), 84 – 91.
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Abstract
The fiber contribution to the ultimate limit state capacity of precast and cast-in situ tunnel linings is analytically investigated. By means of a numerical model, capable of computing the interaction curves of reinforced concrete cross sections subjected to combined compressive and bending actions, the mechanical performances of plain and fiber-reinforced concrete are compared. As a result, a new index is introduced to quantify the effectiveness of fiber addition. The higher the efficiency index, the higher the amount of steel reinforcing bar that can be removed from a plain concrete cross section. The application to real concrete linings, where shear resistance is ensured without shear reinforcement, shows that a large volume of rebar can be saved by the presence of steel fibers. This gives significant advantages in terms of durability and rapidity of tunnel construction.
Keywords
Fiber-reinforced Concrete; Efficiency Index; Ultimate Limit State; Cast-in Situ Concrete Lining; Precast Tunnel Segments
Huang, Ruizhu; Moudon, Anne V.; Zhou, Chuan; Stewart, Orion T.; Saelens, Brian E. (2017). Light Rail Leads to More Walking Around Station Areas. Journal Of Transport & Health, 6, 201 – 208.
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Abstract
Areas around Light Rail Transit (LRT) stations offer ideal conditions for Transit-Oriented Development (TOD). Relatively dense, mixed-use neighborhoods can have positive impacts on mobility, health, and perceptions of neighborhood safety among nearby residents, primarily through walking activity for both transit and other purposes. To examine how station areas may attract new activity, this study analyzed changes in walking around station areas among people living close to an LRT station before and after the opening of a new transit system. This study examined walking behavior among the subset of 214 participants living within one mile of one of 13 LRT stations from among a sample of residents living close or further away from a new LRT line in Seattle. They completed a survey and a travel log and wore an accelerometer and a GPS for 7 days both before (2008) and after the opening of the Seattle area LRT (2010). Walking bouts were derived using a previously developed algorithm. The main outcome was the individual-level change in the proportion of daily walking within one quarter Euclidean mile of an LRT station. Overall walking decreased from before to after the LRT opening while station area walking did not change significantly, indicating a shift in walking activity to the station areas after the introduction of LRT. Increases in the proportion of station area walking were negatively related to participants' distance between home and the nearest LRT station, peaking at .0.75 mile. Male gender, college education, normal weight status, less access to cars, and frequent LRT use were also significantly associated with greater positive changes in the proportion of station area walking. The shift in walking to station areas after the completion of light rail provides evidence that the local proximate population is attracted to station areas, which may potentially benefit both transit use and TOD area economic activity. The residential catchment area for the shift in LRT area walking was < 0.75 mile of the LRT stations. (C) 2017 Elsevier Ltd All rights reserved.
Keywords
Body-mass Index; Physical-activity; Built Environment; Travel Behavior; Transit; Stop; Transit Oriented Development (tod); Behavior Change; Global Positioning Systems; Geographic Information Systems
Sun, Feiyang; Chen, Peng; Jiao, Junfeng. (2018). Promoting Public Bike-Sharing: A Lesson from the Unsuccessful Pronto System. Transportation Research: Part D, 63, 533 – 547.
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Abstract
In 2014, Seattle implemented its own bike-sharing system, Pronto. However, the system ultimately ceased operation three years later on March 17th, 2017. To learn from this failure, this paper seeks to understand factors that encourage, or discourage, bike-sharing trip generation and attraction at the station level. This paper investigates the effects of land use, roadway design, elevation, bus trips, weather, and temporal factors on three-hour long bike pickups and returns at each docking station. To address temporal autocorrelations and the nonlinear seasonality, the paper implements a generalized additive mixed model (GAMM) that incorporates the joint effects of a time metric and time-varying variables. The paper estimates models on total counts of pickups and returns, as well as pickups categorized by user types and by location. The results clarify that effects of hilly terrain and the rainy weather, two commonly perceived contributors to the failure. Additionally, results suggest that users in the University District, presumably mostly university students, tend to use shared bikes in neighborhoods with a higher household density and a higher percentage of residential land use, and make bike-sharing trips regardless workdays or non-workdays. The paper also contributes to the discussion on the relationship between public transportation service and bike-sharing. In general, users tend to use bike-sharing more at stations that have more scheduled bus trips nearby. However, some bike-sharing users may shift to bus services during peak hours and rainy weather. Several strategies are proposed accordingly to increase bike ridership in the future.
Keywords
Bicycle Sharing Programs; Urban Transportation; Transportation & The Environment; Land Use Planning; Time-varying Systems; Bike-sharing; Built Environment; Generalized Additive Mixed Model; Pronto; Temporal Factors; Built Environment Factors; Bicycle; Impact; Transportation; Walking; Usage