Jobs-housing balance in an era of population decentralization: An analytical framework and a case study

Despite the well-established theoretical understanding on the benefits of compact cities to the attainment of sustainable transport goals, there has been a worldwide trend of population decentralization in cities. In this paper, an analytical framework, which can be applied to other cities to quantify the potential commuting travel savings and environmental benefits of different job policies in cities having different rates and patterns of population decentralization, is presented. A case study of Hong Kong in the 1992-2002 decade is used to illustrate the analytical framework. The findings suggest that a city’s population patterns did have significant implications on the commuting travel savings from alternative job relocation policies. With a dispersed population pattern, the expected environmental benefits from a job decentralization policy can be very substantial.     

TRIBUTE: Trip-based urban transportation emissions model for municipalities

This research aims at developing modeling and scenario-comparison tools to explore the impacts of various transportation and land use planning policies on changing travel behavior and eventually greenhouse gas (GHG) emissions. A Trip-Based Urban Transportation Emissions (TRIBUTE) model is developed. Data required for TRIBUTE comes from household travel surveys and emissions inventories, which is a major advantage in cases where a detailed transportation network model is unavailable. TRIBUTE is composed of two main parts: a mode choice model and an emissions forecasting model. The mode choice model is responsible for estimating modal shares of alternative modes of travel in response to changes in personal, modal, and land use attributes. The emissions forecasting model translates the modal shares into vehicle kilometers traveled, and subsequently GHG emissions. TRIBUTE is a macroscopic model intended to assist municipalities evaluate alternative transportation and land use policy scenarios and eventually select the one(s) that help them meet their future GHG emission targets. This paper reports on the conceptual framework of the developed model and presents a case study.     

From a hub port city to a global supply chain management center: a case study of Hong Kong

This paper explores the critical challenges encountered in the transformation process of Hong Kong from a freight transport hub city to a knowledge-based global supply chain management center (GSCMC). The exploration involves an examination of the structural issues of the logistics industry in Hong Kong within the framework of global value chains (GVC). A questionnaire survey and a series of interviews were conducted to reveal the essential problems that the key parties of the Hong Kong logistics industry face if the transition of Hong Kong into a GSCMC is to be successful in all segments of the industry. Through a categorical analysis of logistics segments, the hurdles to the GSCMC as well as the institutional measures are also discussed in this paper.     

Environmental impacts of commuting modes in Lisbon: A life-cycle assessment addressing particulate matter impacts on health

A life-cycle assessment of commuting alternatives is conducted that compares six transportation modes (car, bus, train, subway, motorcycle, and bicycle) for eight impact indicators. Fine particulate matter (PM_2.5) emissions and health impacts are incorporated in the assessment using intake fractions that differentiate between urban and nonurban emissions, combined with an effect factor. The potential benefits of different strategies for reducing environmental impacts are illustrated. The results demonstrate the need for comprehensive approaches that avoid problem-shifting among transportation-related strategies. Policies aiming to improve the environmental performance of urban transportation should target strategies that decrease local emissions, life-cycle impacts and health effects.     

Spatially varying impacts of built environment factors on rail transit ridership at station level: A case study in Guangzhou,China

Understanding the relationship between the rail transit ridership and the built environment is crucial to promoting transit-oriented development and sustainable urban growth. Geographically weighted regression (GWR) models have previously been employed to reveal the spatial differences in such relationships at the station level. However, few studies characterized the built environment at a fine scale and associated them with rail transit usage. Moreover, none of the existing studies attempted to categorize the stations for policy-making considering varying impacts of the built environment. In this study, taking Guangzhou as an example, we integrated multi-source spatial big data, such as high spatial resolution remote sensing images, points of interest (POIs), social media and building footprint data to precisely quantify the characteristics of the built environment. This was combined with a GWR model to understand how the impacts of the fine-scale built environment factors on the rail transit ridership vary across the study region. The k-means clustering method was employed to identify distinct station groups based on the coefficients of the GWR model at the local stations. Policy zoning was proposed based on the results and differentiated planning guidance was suggested for different zones. These recommendations are expected to help increase rail transit usage, inform rail transit planning (to relieve the traffic burden on currently crowed lines), and re-allocate industrial and living facilities to reduce the commute for the residents. The policy and planning implications are crucial for the coordinated development of the rail transit system and land use.     

Preferred shopping destination: Hong Kong versus Singapore

Visitor shopping is an important contributor to the economy of Hong Kong as it accounts for more than half the total visitors' expenditure. Owing to its significance, and strong competition from Singapore, Hong Kong must re‐examine the city's attraction to shoppers. The tourism and retail industries of Hong Kong must formulate effective strategies to identify the strengths and weaknesses of the shopping environment in both cities. This study surveys 309 international visitors about their shopping expectations and perceptions of Hong Kong and Singapore in 15 attributes. Results were analysed by SPSS software (Statistical Package for Social Science) using the techniques of frequencies and paired t‐tests. Singapore outperforms Hong Kong notably in many areas, such as language ability, attitude and efficiency of service staff. The findings indicate an urgency for Hong Kong to strive harder. In conclusion, the article provides some recommendations for the city to re‐establish its reputation as the ‘shopping paradise’ of the Asia Pacific region and to meet the challenge of Singapore as the preferred shopping destination. Copyright © 2004 John Wiley & Sons, Ltd.     

Impacts on travel behaviour of Greater Manchester’s light rail investment (Metrolink Phase 1): evidence from household surveys and Census data

Household survey data from 1990 and 1993 and Census data from 1991 and 2001 are used to detect some short and medium term impacts on travel of the Metrolink light rail services which opened in 1992. Particular attention is paid to research design issues to try to isolate Metrolink’s impacts from those of other influences on travel behaviour. In the short term a more marked decline in the frequency of bus use is found in the Metrolink corridor compared with conventional rail and ‘no rail’ corridors. Changes in the frequency of rail use are more prominent in the Metrolink corridor, both to the highest frequency use but also to lower frequency use. Higher frequency rail use tends to be associated with respondents who have limited or no car availability, who are in employment, who are of non-manual social class and who are aged 18–44 years. Metrolink appears to have attracted at least as many former car users as former bus users, but the former car users tend to use the light rail services less frequently. Census commuting data suggest that, in the medium term, Metrolink has increased rail’s share of trips, especially to the city centre, contributed to the declining share of bus trips and may have helped to restrain work trips by car.     

CO2 emissions associated with hubbing activities in air transport: an international comparison

Hubbing is an important operational practice in air transport. Many studies have been conducted to examine the benefits and impacts of hubbing from an economic perspective. However, its impact on CO₂ emissions, especially across different air spaces, is not well understood. This paper explores the impact of hubbing activities in air transport from an environmental perspective. With a detailed methodology and data from the Greek and Hong Kong/Sanya flight information regions (FIRs), three levels of CO₂ emissions are estimated: airport-based, airspace-based and flight-based. After contrasting the CO₂ emission efficiencies of Athens International Airport (AIA) and the Hong Kong International Airport (HKIA), aircraft type and flight distance are examined to explain their emission efficiency differences. It is found that HKIA is associated with poorer CO₂ emission efficiency at the airport and airspace levels because of the larger aircraft and longer flight distance. However, when CO₂ emission efficiency at the flight level is considered, HKIA, with a higher passenger load factor, performs better. Major international hub airports should implement additional environmental measures to minimize the impact of hubbing activities on CO₂ emissions at the airport and airspace levels.     

Integrating node-place and trip end models to explore drivers of rail ridership in Flanders,Belgium

The node-place model is an analytical framework that was devised to identify spatial development opportunities for railway stations and their surroundings at the regional scale. Today, the model is predominantly invoked and applied in the context of ‘transit-oriented development’ planning debates. As a corollary, these model applications share the pursuit of supporting a transition towards increased rail ridership (and walking and cycling), and therefore assumingly a transition to more sustainable travel behavior. Surprisingly, analyses of the importance of node and place interventions in explaining rail ridership remain thin on the ground. Against this backdrop, this paper aims to integrate the node-place model approach with current insights that derive from the trip end modeling literature. To this end, we apply a series of regression analyses in order to appraise the most important explanatory factors that impact rail ridership in Flanders, Belgium, today. This appraisal is based on both geographical and temporal data segmentations, in order to test for different types of railway stations and for different periods of the day. Additionally, we explore spatial nonstationarity by calibrating geographically weighted regression models, and this for different time windows. The models developed should allow policy and planning professionals to investigate the possible demand impacts of changes to existing stations and the walkable area surrounding them.     

Multiobjective optimization of asphalt pavement design and maintenance decisions based on sustainability principles and mechanistic-empirical pavement analysis

Highway pavement as an important component of transport infrastructure has significant impacts on economy, society, and environment. The management of highway pavement has been traditionally focused on economy. In this study, the impacts of management decisions are examined in three dimensions, including life-cycle cost (LCC), energy consumption, and greenhouse gas (GHG) emissions. Quantitative models to predict the three dimensions are developed from mechanistic-empirical pavement analysis results. Two decision variables, pavement thickness and threshold roughness level for pavement resurfacing, are found to be significant in affecting the three dimensions. These two variables are subsequently used as decision variables in multiobjective optimization. The ranges of decisions that result in minimum LCC, energy consumption, and GHG emissions are identified through multiobjective optimization. Although the analysis is illustrated in the context of pavement design and management in Hong Kong, the analysis techniques and procedures can be easily applied in other regions.     

Near “real-time” estimation of excess commuting from open-source data: Evidence from China's megacities

Urban commuting has continuously fascinated scholars and decision-makers. As few people live and work in the same place, there is always excess commuting (i.e., the non-optimal or surplus work travel occurring in cities because people do not minimize their journeys to work for most residents). Traditional commuting data sources (e.g., questionnaires and census surveys) are challenged by small samples, high cost, and low spatiotemporal resolution. In contrast, the big social-sensing data (e.g., smart card and mobile phone data) only consider one or two traffic mode of a route, which is not consistent with the real-life condition. This article proposes a framework for modeling excess commuting based on open-source data of the ten most populous megacities in China. We downloaded residential points of interest (POIs) from Lianjia Real Estate website and obtained workplace POIs from China's AMAP, which is widespread used as Google map. The stratified sampling approach was employed to derive commuting pairs. Both commuting distance and time were obtained by the shortest path under public transportation from AMAP. Then, the linear programming method was employed to calculate the theoretical minimum commuting time and distance of each city. We analyzed the statistical property and spatial distributions of excess commuting and found that (1) commuting distances and time (ranging from 9.1 to18.1 km and from 44.8 to 74.3  minutes) of all ten megacities follow a left-skewed normal distribution; (2) in terms of commute cost, all cities show universal core-periphery patterns where the spatial heterogeneity of the commuting time is more significant than that of distance; (3) for each city, the excess commuting measured by time (i.e. from 0.61 to 0.79) is lower than that measured by distance (i.e. 0.68 to 0.89); and (4) the role of mixing land use, waterbody distribution, and centripetal urbanization on urban commuting distance and time is significant.     

Exploring multiple eco-routing guidance strategies in a commuting corridor

The introduction of eco-routing systems has been suggested as a promising strategy to reduce carbon dioxide emissions and criteria pollutants. The objective of this study is to scrutinize the impacts of an eco-routing guidance system on emissions through the use of a case study in a commuting corridor. This research aims at assessing the potential environmental benefits in terms of different pollutant emissions. Simultaneously, it addresses the extent of variations in system travel time (S_TT) that each eco-routing strategy implies. The methodology consists of three distinct phases. The first phase corresponds to the adjustment of a microsimulation platform of traffic and emissions with empirical data previously collected. Second, to volume-emission-functions (VEF), developed based on the integrated modeling structure. Final, to different scenarios of traffic flow optimization performed at the network level based on a simplified assignment procedure. The results show that if the traffic assignment is performed with the objective to minimize overall impacts, then the total system environmental damage costs can be reduced up to 9% with marginal oscillations in total S_TT. However, if drivers are advised based on their own emissions minimization, total system emissions may be higher than under the standard user equilibrium flow pattern. Specifically, environmentally friendly navigation algorithms focused on individual goals may tend to divert traffic to roads with less capacity affecting the performance of the remaining traffic. This case study brings new insights about the difficulties and potentials of implementing such systems.     

The spatial characteristics and influencing factors of modal accessibility gaps: A case study for Guangzhou,China

This paper presents an analysis of the spatial characteristic of the modal accessibility gap (MAG) in Guangzhou based on travel times for public transport and cars to public centers calculated by the Travel O-D point Intelligent Query System (TIQS). Four spatial regression models are used to investigate the effect on the MAG of six factors of the built environment (distance to city public centers, residential density, landuse mix, bus stop density, metro station density and road network density). The results show that travel time for a given origin to destination (OD) trip is likely to be larger by public transport than by car, especially for a trip of longer travel time. The MAG values of all the communities are larger than 0, indicating that when compared with public transport, travelling by car takes less travel time for individuals. Residential density, land-use mix, bus stop density and metro rail station density have significant negative direct impacts and indirect impacts (spatial spillover effects) on MAG, which indicates that appropriate increase in community residential density, providing diversified service facilities within a community, and improving public transport supply are beneficial to promote modal shift. Specifically, the role of metro rail is greater than that of buses. However, the road network density has significant direct positive impacts on MAG, and its spillover effect is also significantly positive, which indicates that building more roads is not an effective way to narrow the accessibility gap between public transport and cars but may facilitate more car travel instead.     

Rationalities and materialities of light rail scapes

Light rail is a modernisation of old tram systems and a popular tool in urban development strategies throughout many European cities. Light rails continue to be built despite often having poor socio-economic returns — other similar modes could provide the same transport function at a lower cost. Through a case study, this article explores the main vision and rationalities behind light rail projects in two mid-sized European cities — Bergen and Angers — and considers how this vision has materialised in various ‘light rail scapes’. The article argues that the city shapes the light rail project, but also that the light rail re-configures and shapes the urban structures, design and planning practices within the city based on its materiality and spatial interaction with it. This means that light rail projects need to be rethought as complex urban development projects instead of just simple ‘pieces of infrastructure’. Ultimately, this work seeks to shed light on a number of ideas for future light rail research and practice.     

Tourism planning requirements from a private sector perspective: the case of Hong Kong

Government’s role in tourism planning has shifted from control to consultation, and many governments have adopted economic planning that move the responsibility for investment in infrastructure from the public to the private sector. In Hong Kong, the government has not articulated a clear tourism policy to guide tourism development but continues to assume responsibility for significant tourism infrastructure investment. This paper considers the views of the private sector towards tourism planning in Hong Kong, which gravitate towards the need for a formalized planning. The tourism sector supports the interventionist policies that have been a characteristic of the government’s relationship to the tourism industry in the past, believes that the current approach to planning needs to be replaced by a formal planning process, and that there is a need to include community groups in the policy determination process. The insights gained from the case of Hong Kong may serve as a reference for other destinations.     

Robust accessibility: Measuring accessibility based on travelers' heterogeneous strategies for managing travel time uncertainty

Uncertainties in travel times due to traffic congestion and delay are risks for drivers and public transit users. To avoid undesired consequences such as losing jobs or missing medical appointments, people can manage the risks of missing on-time arrivals to destinations using different strategies, including leaving earlier to create a safety margin and choosing routes that have more reliable rather than fastest travel times. This research develops a general analytical framework for measuring accessibility considering automobile or public transit travelers' heterogeneous strategies for dealing with travel time uncertainty. To represent different safety margin plans, we use effective travel time (expected time + safety margin), given specified on-time arrival probabilities. Heterogeneity in routing strategy is addressed using different Pareto-optimal routes with two main criteria: faster travel time vs. higher reliability. Based on various safety margin and routing strategy combinations, we examine how accessibility changes under varying safety margin plans and routing strategies. Also, we define and measure robust accessibility: geographic regions that are accessible regardless of the safety margin planning and routing strategy. Robust accessibility can provide a conservative and reasonable view of accessibility under travel time uncertainty. To demonstrate the applicability of the methods, we carry out an empirical study on measuring the impacts of new transit service on healthcare accessibility in a deprived neighborhood in Columbus, Ohio, USA.     

The jobs–housing relationship and commuting in Beijing,China: the legacy of Danwei

China’s market-oriented reform has not only revitalized the economy but also changed the physical structure of Chinese cities, which used to be largely determined by the socialist Danwei (or work unit) system. In order to understand the impacts of the reform and the influence of Danwei on jobs–housing relationships and commuting behavior, this study investigates whether there are differences in commuting behavior between individuals who live in houses provided by Danwei and those who reside in houses from private market sources in urban China. We apply the structural equations model to investigate the interactions between housing source (from Danwei or not), jobs–housing relationship, transport mode and commuting time in Beijing, the capital city of China. The results show that Danwei housing commuters have shorter commuting trips and higher usage of non-motorized transport mode than those who live in houses from the market sources. This finding implies that the diminishing influence of the traditional Danwei system and the market-oriented reform in urban development may have changed the jobs–housing balance and increased travel demand in Chinese cities.     

The spatial impacts model of trans-strait fixed links: A case study of the Pearl River Delta,China

The mage trans-strait fixed links are constructed in different countries to promote regional economic and social development. This paper proposes a spatial impacts model for the trans-strait fixed links in the Pearl River Delta, China. To verify the rationality of the model, four quantitative indicators, including weighted average travel time, the economic linkage intensity, the economic linkage membership grade, and the fractal index are used to investigate the effect by construction of Humen Bridge, Hong Kong–Zhuhai–Macao Bridge and Shenzhen–Zhongshan Bridge. The results show that the Hong Kong–Zhuhai–Macao Bridge and Shenzhen–Zhongshan Bridge greatly improve the regional accessibility with a maximum decrease weighted average travel time of 1.38 h and 0.4 h. The central part of the Delta has greatest impacts. The links increase the economic linkage of cities of each side. The cities directly connected to the fixed links (Hong Kong, Shenzhen, Macao and Zhongshan) experience the highest increasing economic linkage. The regional spatial pattern evolves from unipolarity to multi-polarity and integrates a more advanced and sophisticated spatial network. The theoretical spatial impacts model for the trans-strait fixed links accords with the actual development in the Pearl River Delta.     

Strategic travel planning toward future emission targets—A comparative analysis of 20 Swedish municipalities applying the CERO model

Organizations displaying best practices for attaining proactive sustainability targets at local level are of major importance as role models in the transition toward a sustainable transport system. This study summarizes results and conclusions from 20 municipalities in Sweden that have implemented the so called CERO analysis in order to adapt to future emission targets for travel. The overall aim of the study is to identify factors explaining why some municipalities are more successful than others in a benchmarking comparison.

The results indicate that commuting by car is by far the most dominant source of emissions, constituting on average 76% of total annual travel emissions (including both commuting and business travel). In order to reduce these emissions, travel planning programs within organizations must address both commuting conditions and business travel conditions to reduce car dependence for work travel, e.g., employees using private cars for business trips most likely also use their own cars for commuting. To identify potential success factors as regards emissions-efficient travel, three comparative statistical analyses were conducted: grouping municipalities with low emissions in relation to the total average; analysis of car commuters' willingness to change travel mode; and before-and-after analyses of municipalities implementing specific action plans. The results revealed that municipalities conducting follow-up studies 2 years after implementing travel planning programs all lowered their total CO₂ emissions, by on average 10% during a 2-year period. Overall, these municipalities achieved redistribution to alternative travel modes but also reduced total travel mileage.