Impacts on accessibility of China’s present and future HSR network

Although the construction of China’s high-speed rail (HSR) network only started in 2003, the network is already the largest in the world. This paper analyses the impact of the evolving HSR network on the accessibility by HSR and conventional ground transport of 333 prefecture-level cities and 4 municipalities. This paper employs three indicators of accessibility, and analyses three Scenarios. It shows that the HSR network will bring about substantial improvement in accessibility, and lead to national time–space convergence, but will also increase the inequality of nodal accessibility between eastern, central, and western regions, between cities with different sizes of population (excluding the case of the daily accessibility indicator) and between cities that differ in the shortest distance to HSR stations. The HSR network enlarges internal disparities in each of the regions and the five types of cities. The internal inequality of nodal accessibility in all three Scenarios generally increases from the eastern region via the central region to the western region, as well as from very large cities to small cities, varying inversely with the level of economic development and population size. Spatially, accessibility increases generally conform to the distance decay rule but with minor fluctuations. The 50 cities with the largest increases in accessibility are mostly located 50 km or less away from HSR stations and have populations of over 3 million, with the smaller ones located along HSR lines or around large cities such as Beijing, Shanghai, and Guangzhou. As time progresses, the planned HSR network will result in more balanced development, but regional disparities in accessibility will still be greater than before the construction of the HSR.     

Development and test of the Perceived Accessibility Scale (PAC) in public transport

Perceived accessibility, defined as “how easy it is to live a satisfactory life using the transport system”, is proposed to be a complementary measure to conventional, objective measures of accessibility. Aiming at capturing the subjective element of accessibility, as opposed to conventional accessibility that is based on the same objective attributes for large areas or groups of people, the authors developed and tested a measure of perceived accessibility; the four items self-reported Perceived Accessibility Scale (PAC). In study 1, 237 users of public transport rated PAC. The results showed that PAC is a reliable measure. The PAC was further validated and proved reliable in two waves (study 2) in altered conditions (Wave 1, N = 246, Wave 2, N = 259). Based on this, an overall PAC index was constructed. PAC can be used to determine the traveler's (or possible travelers) opinion of accessibility in transport planning or accessibility-mapping, or for directing interventions aimed at improving accessibility to where they are best needed according to the individuals. Further development of the PAC and its potential within transport research and planning, and its future validation is discussed.     

Evaluating accessibility impacts of the proposed America 2050 high-speed rail corridor for the Appalachian Region

Transportation improvements are often considered to be precursors of economic growth. This paper examines industry-specific ‘attractiveness’ due to changes in the transportation network for 23 counties in the Appalachian Region. The network improvements result from new highway construction and the proposed America 2050 High-Speed Rail (HSR) plan for the Piedmont Atlantic Megaregion. The impacted counties that are proximate to five HSR stations (Birmingham, Atlanta, Greenville, Charlotte, and Greensboro) are studied for potential accessibility changes between the years 2002 to 2035. The impacts are examined with respect to six key industry sectors found around the proposed HSR stations: manufacturing; retail; construction; mining, quarrying, oil and gas extraction; health-care services; and all other remaining industries combined. The analysis shows that, for transportation improvements with highways only (and no HSR), a decrease in accessibility for all the impacted counties occurs for the six industry sectors examined in the future year of 2035. The HSR speed of 150 miles per hour is found to be adequate enough to cause positive changes in potential accessibility of the directly impacted counties containing the Birmingham and Greenville HSR stations. With combined transportation network improvements from both highway construction and the new 150 mph HSR line, counties around the Atlanta and Greensboro HSR stations would see accessibility increases in 2035 compared to 2002 with respect to five industry sectors: manufacturing; retail; construction; health-care services; and all other remaining industries combined. However, accessibility changes with respect to mining, quarrying, oil and gas extraction would be positive specifically only for the indirectly impacted counties around the Atlanta HSR station and the county containing the Greenville HSR station. This clearly shows differences in the spatial distribution of attractiveness for different industry sectors across the impacted counties along the HSR corridor. Thus, this exploratory analysis could serve as an aid to proactive public policy decision-making for large-scale transportation network improvements, such as the HSR, in understanding and improving economic activities for different industry mixes across other regions of the United States.     

Detecting urban road network accessibility problems using taxi GPS data

Urban population growth and economic development have led to the creation of new communities, jobs and services at places where the existing road network might not cover or efficiently handle traffic. This generates isolated pockets of areas which are difficult to reach through the transport system. To address this accessibility problem, we have developed a novel approach to systematically examine the current urban land use and road network conditions as well as to identify poorly connected regions, using GPS data collected from taxis. This method is composed of four major steps. First, city-wide passenger travel demand patterns and travel times are modeled based on GPS trajectories. Upon this model, high density residential regions are then identified, and measures to assess accessibility of each of these places are developed. Next, the regions with the lowest level of accessibility among all the residential areas are detected, and finally the detected regions are further examined and specific transport situations are analyzed.By applying the proposed method to the Chinese city of Harbin, we have identified 20 regions that have the lowest level of accessibility by car among all the identified residential areas. A serious reachability problem to petrol stations has also been discovered, in which drivers from 92.6% of the residential areas have to travel longer than 30 min to refill their cars. Furthermore, the comparison against a baseline model reveals the capacity of the derived measures in accounting for the actual travel routes under divergent traffic conditions. The experimental results demonstrate the potential and effectiveness of the proposed method in detecting car-based accessibility problems, contributing towards the development of urban road networks into a system that has better reachability and more reduced inequity.     

Cyclists' exposure to air pollution and road traffic noise in central city neighbourhoods of Montreal

It is well known that bicycling in urban areas has beneficial effects on people's health and well-being. On the other hand, urban cycling, especially during the morning and evening commute, may be associated with health and safety risks due to potentially high levels of exposure to air pollution, road noise, and high traffic density. Few studies have, however, measured cyclists' exposure to noise and air pollution simultaneously.The objective of this research is to evaluate cyclists' exposure to air pollution and noise in central city neighbourhoods of Montreal and to identify the impact on exposure of associated local factors such as weather conditions, the day and time, the type of road, bicycle path or lane used and the characteristics of the immediate environment around the cyclist's route.A total of 85 bicycle trips were analyzed, representing 422 km of travel and nearly 25 h of data collection. The mean exposure levels were 70.5 dB(A) for noise and 76 μg/m³ for nitrogen dioxide (NO₂). A very weak negative correlation was found between the two measures of exposure (R² = − 0.07, p = 0.005).The results of the spatial regression models show that the morning commute and trips on collector roads and on-street bike lanes and shared bike lanes have significant and positive impacts on exposure to air pollution and noise. On the other hand, some factors are only significant for one or the other of the two types of exposure.     

Exploring the relationship between multilevel highway networks and local development patterns—a case study of Taiwan

The relationship between local development patterns and highway networks is complicated, as suggested by studies using various analytical methods. The spatial effects of each hierarchical highway network on local development patterns remains unclear. This study combines space syntax and the hierarchical linear model (HLM) within the research framework in a case study of Taiwan. The former is employed to model the topological accessibility of multilevel highway networks, and the latter is applied to handle the hierarchical relationship between multilevel highway networks and local development patterns. Results indicate a high R-squared (R² = 0.803) value, and statistically significant cross-level interactions are observed. The results show the different spatial effects of various highway networks on the scale of local development patterns, and confirm consideration of highway networks with classification in the research design. The implications of the findings may be appropriate for substantive planning and future research approaches.     

Exploring the impacts of land use by service coverage and station-level accessibility on rail transit ridership

In this study, we employ spatial regression analysis to empirically investigate the impacts of land use, rail service coverage, and rail station accessibility on rail transit ridership in the city of Seoul and the surrounding metropolitan region. Our analyses suggest that a rail transit service coverage boundary of 500 m provides the best fit for estimating rail transit ridership levels. With regard to land use, our results confirm that density is positively related to rail transit ridership within a 750 m radius of each station. In contrast, land use diversity is not associated with rail transit ridership. We also found that station-level accessibility is as important as land use for explaining rail transit ridership levels. Finally, we conclude that development density and station-level accessibility measures such as the number of station entrances or exits and the number of bus routes at the station are the most important and consistent factors for promoting rail transit ridership.     

Improving interchanges in China: the experiential phenomenon

This paper examines the development of multimodal passenger rail hubs as part of the high-speed rail (HSR) network in the People’s Republic of China (PRC). The instrumental, attitudinal and affective experience of the journey through the interchange is assessed from the user perspective. Surveys are used from three HSR stations: Beijing South, Chengdu East and Suzhou North (N = 150), representing three types of HSR stations, i.e. national capital, regional capital and sub-regional city. ‘Expected’ and ‘realised’ facilities are compared – with the difference representing the ‘disgruntlement’ factor (after Stradling et al., 2007).The unprecedented urbanisation process currently being witnessed in the PRC, together with the rapid development of the HSR network and associated multimodal interchanges, offers much opportunity to develop a leading-edge public transport system and urban development predicated on the use of public transport. Although the importance of intermodal interchange hubs is being increasingly recognised, the journey experience through the interchange often remains poor, with problems including Wi-Fi availability, waiting and seating, the availability of door-to-door ticketing, crowdedness, access to the hub, time of travel through and waiting in the hub. MANOVA analysis and factorial (three way) MANOVA analysis are used to explore the differences between intermodal hubs, with many instrumental and particularly attitudinal and affective factors being significantly influenced by location.     

Continuity and change in American urban freeway networks

The American Interstate Highway System was created in 1944, though construction did not commence until 1956. During the planning process for this network the blueprint for American urban freeway systems was set in 1955 by a federal document called the Yellow Book. This provided about 100 maps of cities with planned urban freeway locations for the Interstate Highway System. A set of three basic network patterns were applied to these cities based on their size and location. In the half century since 1955 urban freeways in the Interstate System have expanded from a planned 2000 miles to over 16,600 miles, along with another 11,500 miles of non-Interstate freeways. The number of large metropolitan areas has increased tremendously while the monocentric commuting patterns of have been transformed. This paper explores how these urban freeway systems were applied to the country's urban geography of the 1950s and how they have adapted to changing populations and other transformations in American metropolitan areas in the last half century.     

Spatial interpolation of traffic counts based on origin–destination centrality

This paper presents a new method to estimate Annual Average Daily Traffic. Often traffic volumes are estimated based on roadway characteristics, such as number of lanes, speed limit, and adjacent land use. However, for many communities, especially small communities, these attributes are uniform across roadway types and therefore unable to adequately explain observed variation in traffic volumes. The new method uses novel explanatory variables that are intrinsically derived through a modified form of centrality, a network analysis metric that quantifies the topological importance of a link in a network. The new approach requires minimal data collection and is easily executed using a geographic information system. The case study showed high quality results (out-of-sample validation R² = 0.95). The new approach can be used for various activities related to transportation planning and investment decision making.     

Estimation of travel distances with the weighted ℓp norm: Some empirical results

The weighted ℓ_p or ℓ_k,p norm is used to model travel distances in road networks. The parameters k and p are computed from a sample of actual road distances taken from the geographical area of interest. During the computation, a goodness-of-fit criterion is computed and minimized when the best-fit values of k and p have been determined. Greatly improved results are obtained when the coordinate axes are rotated to account for any rectangular bias in the road network. In this paper, an examination of 17 diverse geographical areas shows that in every case, within a rotation arc of 90°, there are two points where the goodness-of-fit function is minimized. These two rotation points are approximately 45° apart; one results in a best-fit p value in the interval (1, 2) and the other results in a best-fit p value in the interval (2, ∞). This paper thus empirically confirms the double-bottom phenomenon which was hypothesized in a previous work. The superiority of the weighted ℓ_p norm as a distance predictor is also demonstrated.     

Ex-post environmental and traffic assessment of a speed reduction strategy in Madrid's inner ring-road

Since urban traffic is a major source of CO₂ and NO_x emissions, cities play a key role averting climate change and combating air pollution. Most researchers agree on the need of designing comprehensive mitigation strategies instead of applying isolated measures. Nevertheless, it is important to understand the specific impact and scope of each measure to look for the most effective synergies among them. In 2004, the Madrid City Council launched a plan to re-design its inner ring-road to move traffic out of the city centre. For safety reasons the planned speed limit for the full-renovated South-West section was finally reduced from 90 km/h to 70 km/h. Besides contributing to traffic safety, this strategy could also be seen as positive to the environment due to the associated reduced fuel consumption and lower emissions. However, lower speed limits have lower rates of community acceptance due to its impact on average travel times at the individual level. This paper conducts an ex-post evaluation of this speed reduction strategy to explore its environmental and traffic performance impacts. The results support the thesis that, in this velocity range, lower speed limits present important opportunities for reducing GHG and air pollution in the section affected by the measure, without substantially altering traffic performance. The implementation of the new speed limit policy produces a 14.4% and 16.4% reduction in CO₂ and NO_x emissions respectively, while global travel time remains virtually constant and the saturation rate decreases slightly. Besides, this cost-effective measure reveals great potential to reduce air pollution in highly populated urban areas located next to urban highways. This work provides local policy makers and city managers with useful insights regarding potential co-benefits of traffic optimization and speed reduction management to reduce mobile source emissions in urban environments.     

Methods for deriving and calibrating privacy-preserving heat maps from mobile sports tracking application data

Utilization of movement data from mobile sports tracking applications is affected by its inherent biases and sensitivity, which need to be understood when developing value-added services for, e.g., application users and city planners. We have developed a method for generating a privacy-preserving heat map with user diversity (ppDIV), in which the density of trajectories, as well as the diversity of users, is taken into account, thus preventing the bias effects caused by participation inequality. The method is applied to public cycling workouts and compared with privacy-preserving kernel density estimation (ppKDE) focusing only on the density of the recorded trajectories and privacy-preserving user count calculation (ppUCC), which is similar to the quadrat-count of individual application users. An awareness of privacy was introduced to all methods as a data pre-processing step following the principle of k-Anonymity. Calibration results for our heat maps using bicycle counting data gathered by the city of Helsinki are good (R² > 0.7) and raise high expectations for utilizing heat maps in a city planning context. This is further supported by the diurnal distribution of the workouts indicating that, in addition to sports-oriented cyclists, many utilitarian cyclists are tracking their commutes. However, sports tracking data can only enrich official in-situ counts with its high spatio-temporal resolution and coverage, not replace them.     

PM,NOx and CO2 emission reductions from speed management policies in Europe

Speed reduction measures rank among the most common schemes to improve traffic safety. Recently many urban streets or entire districts were converted into 30 kph zones and in many European countries the maximum permissible speed of trucks on motorways is under discussion. However, besides contributing to traffic safety, reducing the maximum speed is also seen as beneficial to the environment due to the associated reduced fuel consumption and lower emissions. These claims however are often unsubstantiated.To gain greater insight into the impact of speed management policies on emissions, this paper examines the impact on different traffic types (urban versus highway traffic) with different modelling approaches (microscopic versus macroscopic). Emissions were calculated for specific types of vehicles with the microscopic VeTESS-tool using real-world driving cycles and compared with the results obtained using generalized Copert-like macroscopic methodologies. We analyzed the relative change in pollutants emitted before and after the implementation of a speed reduction measure for passenger cars on local roads (50–30 kph) and trucks on motorways (90–80 kph). Results indicate that emissions of most classic pollutants for the research undertaken do not rise or fall dramatically. For the passenger cars both methods indicate only minor changes to the emissions of NO_x and CO₂. For PM, the macroscopic approach predicts a moderate increase in emissions whereas microscopic results indicate a significant decrease. The effects of specific speed reduction schemes on PM emissions from trucks are ambiguous but lower maximums speed for trucks consistently result in lower emissions of CO₂ and lower fuel consumption. These results illustrate the scientific uncertainties that policy makers face when considering the implementation of speed management policies.     

A supply chain network design model for biomass co-firing in coal-fired power plants

We propose a framework for designing the supply chain network for biomass co-firing in coal-fired power plants. This framework is inspired by existing practices with products with similar physical characteristics to biomass. We present a hub-and-spoke supply chain network design model for long-haul delivery of biomass. This model is a mixed integer linear program solved using benders decomposition algorithm. Numerical analysis indicates that 100 million tons of biomass are located within 75 miles from a coal plant and could be delivered at $8.53/dry-ton; 60 million tons of biomass are located beyond 75 miles and could be delivered at $36/dry-ton.     

Territorial cohesion impacts of high-speed rail under different zoning systems

Large-scale transport infrastructure projects such as high-speed rail (HSR) produce significant effects on the spatial distribution of accessibility. These effects, commonly known as territorial cohesion effects, are receiving increasing attention in the research literature. However, there is little empirical research into the sensitivity of these cohesion results to methodological issues such as the definition of the limits of the study area or the zoning system. In a previous paper (Ortega et al., 2012), we investigated the influence of scale issues, comparing the cohesion results obtained at four different planning levels. This paper makes an additional contribution to our research with the investigation of the influence of zoning issues. We analyze the extent to which changes in the size of the units of analysis influence the measurement of spatial inequalities.The methodology is tested by application to the Galician (north-western) HSR corridor, with a length of nearly 670 km, included in the Spanish PEIT (Strategic Transport and Infrastructure Plan) 2005–2020. We calculated the accessibility indicators for the Galician HSR corridor and assessed their corresponding territorial distribution. We used five alternative zoning systems depending on the method of data representation used (vector or raster), and the level of detail (cartographic accuracy or cell size). Our results suggest that the choice between a vector-based and raster-based system has important implications. The vector system produces a higher mean accessibility value and a more polarized accessibility distribution than raster systems. The increased pixel size of raster-based systems tends to give rise to higher mean accessibility values and a more balanced accessibility distribution. Our findings strongly encourage spatial analysts to acknowledge that the results of their analyses may vary widely according to the definition of the units of analysis.     

Planning for competitive port expansion on the U.S. Eastern Seaboard: the case of the Savannah Harbor Expansion Project

With the expansion of the Panama Canal, port cities along the U.S. Eastern Seaboard are competing to attract the increased trade expected once the project is complete in 2015. Competition includes extensive investment in projects for port expansion, dredging, and multimodal transportation for greater hinterland connectivity, fueled in part by uncoordinated federal port investments without a larger strategic vision for national port and trade infrastructure. One of the competing ports is in Savannah, Georgia, which is the country’s fourth busiest container port. Savannah is about to embark on a $652 million project that will dredge thirty-two miles of the Savannah River from 42 to 47 feet to attract and accommodate Post-Panamax container ships. The paper analyzes the geographic coastal impacts of port competition, and looks at the unique circumstances of the Greater Savannah Metropolitan Region in planning for future growth of its port. The case illustrates the geographic tensions of uncoordinated maritime freight and logistics planning with fragile coastal and riparian ecologies. The dramatic interventions in port excavation also demonstrate how global forces of technological change and port expansions in other parts of the world are reshaping local geographies.     

Social influence in the global diffusion of alternative fuel vehicles – A meta-analysis

Alternative fuel vehicle technologies are needed to mitigate rising greenhouse gas emissions from transport. Social influence is integral to the diffusion of private vehicles which are highly visible and fulfil practical as well as social functions. This paper provides the first meta-analysis of empirical studies which measure the strength of social influence on consumer vehicle choice. A systematic literature review identified 21 studies that examined three types of social influence: interpersonal communication; neighbourhood effect; and conformity with social norms. A random effects meta-analysis found a significant and small to moderate effect of social influence on vehicle choices (r = 0.241, p < 0.001). The overall effect size did not vary significantly between types of social influence nor between types of vehicle (conventional or alternative fuel). However, further analysis using meta-regression found that heterogeneity in social influence effect size across studies was explained by differences in countries' cultural receptiveness to normative influence. These findings have important implications for policy and modelling analysis of alternative fuel vehicle adoption, for which diffusion is both a socially and culturally-mediated process.     

Rebuilding women's livelihoods strategies at the city fringe: Agency,spatial practices,and access to transportation from Semmencherry,Chennai

Existing debates suggest that resettlement leads to exclusion of the urban poor from the city, linked to interrupted livelihoods and lack of accessibility to the city. This paper analyses the ways in which public transport mobility plays a role in the livelihood strategies of women living in a resettlement area at the fringe of Chennai, India. The main question addressed is how women exercise agency in embedding spatial practices within their livelihood strategies to reconnect to the city.The analysis is based on 4 months fieldwork in Semmencherry Resettlement Area in Chennai (India). It combines a qualitative analysis with a spatial exploration drawing on concepts from debates on the livelihoods approach, spatial practices, and accessibility and transport-related exclusion. Results show that the more agency women have to negotiate livelihoods strategies, the better they can take complex decisions on accessing resources over large distances and minimizing their adverse effects.We argue that combining a livelihood with a spatial analysis is important because it shows how spatial exclusion has to be assessed according to women's own priorities and decisions concerning spatial practices as part of livelihoods strategies. Accessibility and recreating relational spaces may both widen women's opportunities as well as overstretch their physical and financial resources.