Did highways cause the urban polycentric spatial structure in the Shanghai metropolitan area?

Based on LandScan population data, land use data and highway data for the Shanghai metropolitan area from 2000 to 2015, this paper studies the impact of highways on the formation of built-up areas and subcenters to explain the emergence of the urban polycentric spatial structure. The findings are as follows. (1) The dispersion of the population strengthens the polycentric spatial structure of the Shanghai metropolitan area. From 2000 to 2015, the number of subcenters increased from 72 to 118, and their area expanded from 1347 km² to 3469 km². In addition, the main centers lost 12.7% of the population share, while the subcenters gained 12.47% of the population share. (2) Highways play a significant role in promoting urban spatial expansion and the formation of subcenters in the Shanghai metropolitan area. With every 1% decrease in distance to the nearest highway, the probability of an undeveloped area becoming a built-up area increases by 1.53–6.74%, and the probability of a built-up area becoming a subcenter increases by 11.93–20.92%. The results are robust to a series of supplementary tests, such as the replacement of explained variables or explanatory variables and the adoption of instrumental variables. (3) The Chinese government plays an important role in urban polycentric spatial development. New district and development zone policies represent two important mechanisms of highways affecting urban polycentric spatial development.     

The determinants of growth of employment subcenters

This paper presents an empirical analysis of subcenter growth. We develop a series of hypotheses based on the theoretical concepts that have been proposed as explanations for the emergence and growth of subcenters. We then conduct tests of these hypotheses using 1970–80 data from the Los Angeles region. We find that subcenters containing fast-growing industries tended to grow rapidly, and so did those close to airports. There is weak evidence that large subcenters and those located near downtown Los Angeles grew more slowly in proportional terms, possibly indicating diseconomies of scale due to congestion.     

The geography of freight-related accidents in the era of E-commerce: Evidence from the Los Angeles metropolitan area

Due to the burgeoning demand for freight movement in the era of e-commerce, freight related road safety threats have been growing in both urban and suburban areas, despite the improved general traffic safety over the past decades. The empirical evidence on how freight trucks related crashes are distributed across neighborhoods and correlated to spatially varying factors is, however, highly limited. This article uses data from the Los Angeles region in 2018 to analyze the spatial patterns of freight trucks related traffic crashes and examines the major factors that contribute to those patterns using spatial econometric models. Maps show that freight trucks related crashes are highly associated with major freight generators but less clustered than the overall traffic crashes. Results from the spatial Durbin model indicate that access to freight generators, economic attributes, land uses, road infrastructure, and road network variables all contribute to the spatial distribution of freight trucks related crashes. The findings could help transport planners understand the dynamics of freight trucks related traffic safety and develop operational measures for mitigating the impacts of growing goods movement on local communities.     

Commuting and energy consumption: toward an equitable transportation policy

Like other major metropolitan areas, the urban complex that extends from Los Angeles to Orange County faces numerous transportation challenges. Daily traffic congestion, reduced productivity and loss of income, air pollution, environmental degradation and significant energy consumption are only a few outcomes of the millions of miles travelled every day on the region’s highways and streets. An important response to this significant urban challenge has been the desire for further expansion of an efficient public transportation network and increasing densities in particular areas within the larger metropolitan region. In this paper, we estimate the current energy consumption patterns in various communities, arguing that policy attempts to achieve higher density and better jobs-housing balance should fully consider the social geography of our metropolitan areas and their close relationship with energy consumption patterns.     

Understanding the travel behaviors and activity patterns of the vulnerable population using smart card data: An activity space-based approach

Understanding the travel behaviors and activity patterns of vulnerable people is important for addressing social equity in urban and transportation planning. With the increasing availability of large-scale individual tracking data, new opportunities have emerged for studying people's travel behaviors and activity patterns. However, the data has not been fully exploited to examine the travel characteristics of vulnerable people and their implications for understanding transport-related disadvantage. This study proposes a methodological framework based on the concept of activity space that enables a comprehensive examination of vulnerable people's spatiotemporal travel characteristics and an investigation of the geographies of transport disadvantage. Using the proposed framework, a case study that investigates the bus activities of the vulnerable population using four-month smart card data is carried out in the city of Wuhu, China. The case study suggests that vulnerable people possess distinct travel behaviors that differ considerably from the mainstream population and that the implications of transport disadvantage, as revealed by the participation in bus activities, vary across different demographic groups and across different spatial contexts. Some of the empirical insights obtained from this study also differ from conclusions drawn from previous studies and will enrich our understandings of vulnerable people's activities. Overall, the paper makes two major contributions. Methodologically, the proposed framework can overcome some of the deficiencies of activity space-based approaches for understanding transport disadvantage and contribute broadly to the studies of travel behaviors and activities patterns using individual-level tracking data. Empirically, the study identifies varying spatial and temporal implications of transport disadvantage associated with different vulnerable groups, which could further shed light on public transit planning and service design.     

Spatial patterns of logistics facilities in Gothenburg,Sweden

In recent years, the location of logistics facilities, in particular with regard to “logistics sprawl,” has emerged as a topic in the literature that is, a process of spatial decentralisation of logistics facilities in large metropolitan areas. The aim of this paper is to look at logistics sprawl patterns in the Gothenburg metropolitan area, in the south-west of Sweden. Looking at a medium-size monocentric urban region that is also a major port gateway for the country, this study provides novel elements in the study of locational patterns of freight facilities in metropolitan areas. It also provides an opportunity to identify the role of freight in planning, land use and zoning policies. A literature review is carried out on the issues of freight and logistics facilities locational patterns. A quantitative analysis is proposed, using data from Swedish statistics about the number of establishments with a NACE code related to logistics, as well as an original method providing a “cleaned” and more comprehensive dataset. We look at data at two different scales, one metropolitan and one regional, for years 2000 and 2014, as to enable a comparative and diachronical analysis. Logistics sprawl is measured by the average distance of warehouses to their common centre of gravity. Finally, interviews with transport and logistics providers as well as real estate investors and public agencies in the region, add qualitative information on the relative importance of different location factors related to logistics facilities and the issues raised. Logistics sprawl in Gothenburg occurs in specific ways, and differently at the two geographical levels of analysis.     

The geography of air freight: connections to U.S. metropolitan economies

Despite the rapid growth of air freight shipments, much of the existing literature on the geography of air transportation has paid more attention to passenger travel than air freight. The purpose of this paper is to elevate our understanding of air freight by determining which specific variables most influence and shape the geographic distribution of air freight by metropolitan area using stepwise regression analysis. The empirical results suggest a regression model of five independent variables was the most parsimonious solution where the final model accounted for 71.1% of the variation in air freight shipments by metropolitan area (MA). The most important predictor was the traffic shadow effect, where less populated MAs under the traffic shadow of larger MAs tended to generate lower levels of freight. The model also suggested that other key predictors included the employment market share in transportation-shipping-logistics industries, per capita personal income, the number of medical diagnostic and supplier establishments, and above average wages in high technology. Overall, metropolitan markets with diverse and efficient ground support systems, freight forwarders and other transportation services, a more affluent population, an intense agglomeration of medical laboratories and related suppliers, and a well paid skilled workforce engaged in computer systems design and electronic product manufacturing are more likely to ship freight by air.     

Spatial context and the complexity of daily travel patterns: an international comparison

The analysis of travel patterns is an important research topic in transportation research and urban planning. It provides the background information necessary to better understand the complex relationship between urban structure, the transportation system and household travel patterns. To what extent do travel behaviour reflect the properties of the urban structure and the transportation network, or do these patterns largely follow their own regularities? Can different patterns be observed across different space-time settings, or can common patterns be observed, largely independent from such contexts? To better understand these relationships, this paper reports on some of the findings of analyses, conducted to identify underlying structures in various aspects of travel patterns. Travel patterns, derived from activity and travel diary data collected in Portland (USA), Midlands (UK), Fukuoka (Japan), Canadian metropolitan areas, and the South-Rotterdam region (The Netherlands) are compared. The results indicate that travel patterns are largely independent from spatial setting, except for some extreme cases.     

The impact of metropolitan,county, and local land use on driving emissions in US metropolitan areas: Mediator effects of vehicle travel characteristics

Many municipalities in the U.S. pursue compact development to reduce greenhouse gas (GHG) emissions from driving. Despite the efforts, however, recent studies suggest that some land use strategies such as densification and mixed-use development may result in slower vehicle movements, and consequently generate more driving emissions. Since vehicle miles of travel (VMT) is only a proxy and not an exact measure of emissions, reduction in VMT may not lead to a proportional reduction in transportation GHG emissions. Aside from local land use efforts, regional factors also influence vehicle travel and associated emissions.This study investigates the relationship between land use, vehicle travel, and driving emissions in the selected U.S. metropolitan areas at multiple geographic levels. The study employed structural equation modeling (SEM) techniques to examine how land use influences vehicle travel characteristics and associated emissions. The main data sources for the analyses include the 2009 National Household Travel Survey (NHTS) add-on samples and the Smart Location Database (SLD) from the U.S. Environmental Protection Agency (EPA). The study results show that VMT reduction and the associated environmental benefit do not show a one-on-one relationship due to the emissions penalty of lowered vehicle operating speed. Vehicle travel and associated emissions are not only influenced by local urban form factors but also affected by the greater geographical context.     

Why do warehouses decentralize more in certain metropolitan areas?

Over the last decade, warehousing and distribution centers have decentralized to the urban peripheries where land is cheaper and readily available. This change in location patterns has been driven by the demand to build more modernized and larger facilities to accommodate an ever-increasing influx of freight. Since efficient freight movement is essential for the smooth functioning of metropolitan areas, decentralization should occur everywhere. However, this is not necessarily true. It is hypothesized that depending on the volume of goods movement and the spatial distribution of land prices, the extent of decentralization varies across metropolitan areas. This hypothesis is tested using 48 US metropolitan areas. Results provide robust evidence that high land prices push large warehouses away from central locations. When freight demand and land prices are not as high, the effect becomes insignificant. Indeed, not only is decentralization linked with large metro areas but also with very large warehouses.     

Division of labour and gender differences in metropolitan car use: An empirical study in Cologne,Germany

This paper suggests the need for a broader view of `gender and transport' by presenting a study of gender differences in car use for maintenance travel. Although many more women are now entering the labour force than a few decades ago, they still have to undertake the larger share of household-related work. The main objective of this paper is to assess the impact of these changing gender roles on travel patterns and in particular on car use for maintenance travel. We used the survey and trip diary data of 949 respondents living in two urban and two suburban neighbourhoods of the Cologne metropolitan area. The empirical findings suggest that labour market and maintenance activities influence car use in different directions. While parenthood reduces the odds of car use by women, it increases men's car use. Labour force participation on the other hand, especially when part-time, intensifies car use for both genders. In short, a levelling influence of paid work and a traditionalizing influence of parenthood regarding car use for maintenance travel was found.     

An evaluation of logistics sprawl in Chicago and Phoenix

This paper evaluates whether or not there is a sprawling tendency to the spatial patterns of warehouse establishments in the Chicago and Phoenix metropolitan areas. The trend of warehouses to move away from the urban centers to more suburban and exurban areas is referred to as “Logistics Sprawl”. To measure sprawl, the barycenter of warehousing establishments was compared to the barycenter of all other industry establishments in the region between the years of 1998 and 2013 for Chicago; 1998 and 2015 for Phoenix. This shows that logistics sprawl is a behavior experienced by warehouses in the Chicago area, but not in the Phoenix area. This paper discusses if logistics sprawl is a national trend or a regional behavior by comparing these results to the previous case studies of the Atlanta, Los Angeles, and Seattle metropolitan areas.     

Revealing travel patterns and city structure with taxi trip data

Delineating travel patterns and city structure has long been a core research topic in transport geography. Different from the physical structure, the city structure beneath the complex travel-flow system shows the inherent connection patterns within the city. On the basis of taxi-trip data from Shanghai, we built spatially embedded networks to model intra-city spatial interactions and to introduce network science methods into the analysis. The community detection method is applied to reveal sub-regional structures, and several network measures are used to examine the properties of sub-regions. Considering the differences between long- and short-distance trips, we reveal a two-level hierarchical polycentric city structure in Shanghai. Further explorations of sub-network structures demonstrate that urban sub-regions have broader internal spatial interactions, while suburban centers are more influential on local traffic. By incorporating the land use of centers from a travel-pattern perspective, we investigate sub-region formation and the interaction patterns of center–local places. This study provides insights into using emerging data sources to reveal travel patterns and city structures, which could potentially aid in developing and applying urban transportation policies. The sub-regional structures revealed in this study are more easily interpreted for transportation-related issues than for other structures, such as administrative divisions.     

Dependence between travel distance,individual socioeconomic and health-related characteristics,and the choice of the travel mode: a cross-sectional study for Kaunas,Lithuania

The aim of this study was to analyse the associations between individual socioeconomic and health-related characteristics, travel distance, and the choice of different travel modes in urban population. A cross-sectional study included 932 adults of Kaunas city, Lithuania. The choice of the travel mode and individual characteristics were self-reported by the participants, and their travel routes were calculated using the geographic information system. Multivariate logistic regression was used to assess the most significant factors determining the choice of a car, cycling, walking, or public transport. In total, 529 participants reported using a car, of whom 65.8% had medium or high education levels. These participants were more likely to be younger, male, married, and employed. Among bicycle users, statistically significant differences between the employment status, body mass index, and travel distance were observed. Walkers were significantly more likely to be older, those with lower incomes, unemployed, and travelling the shortest distances. The analysis of the travel distance on the choice of the travel mode revealed that men travelled longer distances with a car compared to women. The employment status was significantly associated with travel distance by car or public transport. Employed individuals travelled longer distances by public transport or by car, compared to unemployed individuals. Among bicycle users, we found that people with higher levels of education and overweight individuals cycled the longest distances. Our study emphasizes the importance of considering different individual characteristics when analysing the choice of transport modes. It provides evidence that is relevant for all urban populations on the choice of the transport mode, particularly considering active versus passive transport.     

Long-distance trips in a sparsely populated region: The impact of high-speed infrastructures

This paper aims to analyze the different territorial performance of two new high-speed transport infrastructures, a national motorway and a high-speed rail (HSR) line, with an emphasis on their different roles on long-distance trip making, in a peripheral and sparsely populated province of Spain, contributing to the existing limited research on the influence of high-speed transport infrastructures on urban structure and mobility of sparsely populated regions.The paper provides empirical evidence by means of a mobility survey. The analysis of modal split, travel frequencies, and travel purposes allows a better understanding of long-distance mobility patterns and establishes different travel profiles. The study of commuting and discretionary flows shows different levels and types of metropolitan integration depending on the type of connection and on local characteristics.     

Does the built environment make a difference? Additional evidence from the daily activity and travel behavior of homemakers living in New York City and suburbs

Homemakers, unlike employed people who have jobs and unemployed people who are seeking jobs, are a special group who do not have to spend time working out of the home, commuting to work, or looking for a job. Given that a regular job typically takes 9 h (This includes an assumed half-hour one-way commute time.) a day, the discretion to allocate their time is presumably much greater than other groups.In this paper, we focus our attention on homemakers’ activity and travel behavior in neighborhoods with different characteristics (e.g., very dense areas, dense areas, and suburbs). The question to be answered is quite simple: are there differences between travel behaviors of homemakers living in different types of neighborhoods? If yes, can these differences be attributed to differences in the built environment?The dataset used in the study is the Household Interview Survey (HIS) collected in 1997/1998 in the New York metropolitan area. We found significant differences in activity and travel related behavior by homemakers living in different types of neighborhoods. Compared to suburban homemakers, New York City homemakers spend more time on discretionary activities and less time on maintenance activities; use public transportation and walk more frequently; and conduct fewer trip chains. The study found that both individuals’ socio-economic characteristics and built environment appear to play a role in explaining behavior. A probably more important factor in explaining people’s time use behavior is the interrelationship between activities and trips, and between different types of activities.     

Locational determinants of major US air passenger markets by metropolitan area

The paper examines the influence of metropolitan characteristics in determining the locations of major air traffic markets in the US. In general, the likelihood of a major air passenger market locating in any given metropolitan area is primarily determined by the metropolitan area's population size and overall propensity for air travel. The study shows that on average, a major air passenger market has over 3 million people while a minor market has a population base of about 760,000. The propensity of a population to fly is mainly a function of a number of social and economic indicators, the most important of which was found to be employment in professional–scientific–technical services and management activities.     

Big data for big issues: Revealing travel patterns of low-income population based on smart card data mining in a global south unequal city

Smart card data (SCD) allow analyzing mobility at a fine level of detail, despite the remaining challenges such as identifying trip purpose. The use of the SCD may improve the understanding of transit users' travel patterns from precarious settlements areas, where the residents have historically limited access to opportunities and are usually underrepresented in surveys. In this paper, we explore smart card data mining to analyze the temporal and spatial patterns of the urban transit movements from residents of precarious settlements areas in São Paulo, Brazil, and compare the similarities and differences in travel behavior with middle/high-income-class residents. One of our concerns is to identify low-paid employment travel patterns from the low-income-class residents, that are also underrepresented in transportation planning modeling due to the lack of data. We employ the k-means clustering algorithm for the analysis, and the DBSCAN algorithm is used to infer passengers' residence locations. The results reveal that most of the low-income residents of precarious settlements begin their first trip before, between 5 and 7 AM, while the better-off group begins from 7 to 9 AM. At least two clusters formed by commuters from precarious settlement areas suggest an association of these residents with low-paid employment, with their activities placed in medium / high-income residential areas. So, the empirical evidence revealed in this paper highlights smart card data potential to unfold low-paid employment spatial and temporal patterns.     

Impacts of two-scale urban form and their combined effects on commute modes in U.S. metropolitan areas

This study explores the relationship between urban form at the metropolitan and neighborhood scales and the percentages of four individual modes to commute. It then looks at the combined effects of urban forms at the metropolitan scale in metropolitan areas in the continental United States using multi-level regression models with interactive terms between urban forms. This study contains the percentages for four commute modes: percentage of the vehicle (VT), public transit (PT), biking (BI), and walking (WK). As urban form factors, this study contains urban fragments, population density, job-resident balance (JRB), the percentage of green areas at the metropolitan scale, and distance to the nearest job center at the neighborhood scale. The results show that at the neighborhood scale, a farther distance from individual neighborhoods to the nearest job center is associated with higher VT, and lower PT, BI, and WK. At the metropolitan scale, urban form factors have a more significant association with the percentage of individual modes to commute in large MSAs compared with small MSAs in terms of population. Most urban form factors at the metropolitan scale are not independently associated with the use of commute modes, but their interactions are associated with the percentage of individual modes to commute. Particularly, the level of urban fragments and the percentage of green areas may transform the impact of high population density and JRB on the percentage of the individual modes to commute except for WK. This study provides planners and policymakers with important guidelines to establish combined urban form plans rather than single urban form oriented plans to reduce vehicle travel.     

Key research themes on ICT and sustainable urban mobility

Abstract

Information and communication technologies (ICTs) are hypothesized to replace or change the use of the transport system by facilitating new or different activities. This article offers a review of more than 40 years of research regarding the relationship between ICTs and urban mobility. We discuss the expectations for the changes in travel demand, travel patterns, and the urban form as a result of the development and introduction of ICTs. Much of the interest in the relationships between ICTs and mobility is premised on the expectation of substitution effects, but empirical findings often suggest more complex effects than direct substitution. Although research on single types of travel activity may sometimes indicate simple substitution effects, examination of the broader impacts may also reveal travel generation effects as well. As such, ICTs do not simply substitute mobility patterns but change them. A growing body of research focuses on changing mobility patterns (in terms of time and space), changes in the experience of travel and changes in the perceptions of travel costs due to the interaction between old and new technologies for overcoming distance. ICTs are gradually becoming embedded within the transport system, enabling flexibility, multitasking, and an increase in human activities.