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.     

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.     

Trading off public values in High-Speed Rail development in China

Theory on how different public values are prioritized in transport infrastructure planning is growing increasingly sophisticated, but most of it has focused on Western countries. Its relevance to China is thus far unknown territory. In this article, we apply the theory on public values and the way various values are traded off against each other to the case of High-Speed Rail development in China. We develop a Public value tradeoff matrix enabling us to identify and measure the various public values at play and to establish what changes took place in the prioritization of various public values over time. In the history of HSR development in China, a shift from regional equity and safety through economic growth and speed to organizational efficiency and cooperation can be observed in the period before HSR took off in China until now. The trading off process takes place through different institutional paradigms and organizational mechanisms in China than in Europe and America, and occurs more at the strategic apex of the administrative hierarchy.     

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.     

Active-transport walking behavior: destinations,durations, distances

This paper fills a gap in our knowledge of active-transport (AT) walking, by presenting detailed aspects of walking behavior for a medium-sized North American city. It analyzes the frequency and length of walking episodes, categorized by origins, purposes, and destinations, and also investigates distance-decay functions for major destinations. The study employs day-after recall time diary and questionnaire data from the 2007–8 Space–Time Activity Research (STAR) survey conducted in Halifax, Canada. GPS co-ordinate data enhanced the accuracy of location information, start times, and end times of the 1790 AT walking episodes, while GIS software was used to compute a shortest-path distance between the origin and destination of each episode.Home is both the most common origin and destination for AT walks, and the most common purpose is travel-to-shop rather than travel-to-work. Most walks are to non-home locations, such as retail establishments and offices. Particularly important are restaurants and bars, grocery stores, shopping centers, banks, and other services. All major destinations show strong distance-decay effects: most walks are shorter than 600 m, and very few exceed 1200 m. The assumption employed in the walkability literature, that one should restrict the ‘neighborhood of opportunity’ to walking destinations within 1000 m of the home, is seen to be well justified. However, a planning policy focus on the walker’s home neighborhood is revealed as questionable, since the majority of walking trips do not originate from the home. The relationship between urban land-use patterns and walkability may therefore require some rethinking.     

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.     

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.     

Vertical relations in the air transport industry: A facility-rivalry game

This paper investigates contracts between airports and airlines, in the context of two competing facilities and three types of agreements. The downstream market consists in a route operated by one leader and n ? 1 followers competing à la Stackelberg in each facility. We develop a multistage game where each airport and its dominant airline decide whether to enter into a contract and which one to engage in. We find that the airport and its dominant airline have incentives to collude in each facility. Nevertheless, the equilibrium is not efficient in terms of social welfare: there is a misalignment between private and social incentives.     

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.     

Ride-sourcing compared to its public-transit alternative using big trip data

Ride-sourcing risks increasing GHG emissions by replacing public transit (PT) for some trips therefore, understanding the relation of ride-sourcing to PT in urban mobility is crucial. This study explores the competition between ride-sourcing and PT through the lens of big data analysis. This research uses 4.3 million ride-sourcing trip records collected from Chengdu, China over a month, dividing these into two categories, transit-competing (48.2%) and non-transit-competing (51.8%). Here, a ride-sourcing trip is labelled transit-competing if and only if it occurs during the day and there is a PT alternative such that the walking distance associated with it is less than 800 m for access and egress alike. We construct a glass-box model to characterise the two ride-sourcing trip categories based on trip attributes and the built environment from the enriched trip data. This study provides a good overview of not only the main factors affecting the relationship between ride-sourcing and PT, but also the interactions between those factors. The built environment, as characterised by points of interest (POIs) and transit-stop density, is the most important aspect followed by travel time, number of transfers, weather, and a series of interactions between them. Competition is more likely to arise if: (1) the travel time by ride-sourcing <15 min or the travel time by PT is disproportionately longer than ride-sourcing; (2) the PT alternative requires multiple transfers, especially for the trips happening within the transition area between the central city and the outskirts; (3) the weather is good; (4) land use is high-density and high-diversity; (5) transit access is good, especially for the areas featuring a large number of business and much real estate. Based on the main findings, we discuss a few recommendations for transport planning and policymaking.     

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.     

Complaints caused by aircraft operations: an assessment of annoyance by noise level and time of day

The impact of aircraft movements on the local community surrounding an international airport was investigated using airport data on complaints, noise monitoring, aircraft flight paths and movements to assess annoyance due to noise level and time-of-day. As predicted, the louder the noise the more complaints were generated, with twice the complaints per movement at 110–114 PNdB compared with 74–79 PNdB.The hourly patterns in flight frequency and complaints were clearly distinct. Calculations of the complaints per aircraft movement for each hour of the day showed a striking 24 h pattern with night flights (23.00–06.00) causing on average nearly five times more complaints than the rest of the day (06.00–23.00). The time of the greatest propensity to complain about aircraft noise was between 01.00 and 02.00 and the lowest between 08.00 and 09.00.The circadian pattern in sensitivity to aircraft noise could be used to inform the development of airport operations and flight movements to minimize community disturbance.     

Design speeds and acceleration characteristics of bicycle traffic for use in planning,design and appraisal

This paper reports the results of a study of a cohort of cyclists to determine their speed and acceleration characteristics relative to gradient and other influencing factors in order to supply data for planners, designers and appraisers of cycle infrastructure schemes. A cohort of everyday cyclists was supplied with a global positioning system device and a heart rate monitor and asked to collect data from their journeys in Leeds, UK.The analysis determines the cyclists’ speeds and accelerations at every point on their journey and elevation data, corroborated by mapping information, was used to determine the gradient. Two linear regression models of speed and acceleration were estimated and show that the influence of a downhill gradient on speed is less pronounced than the effect of an uphill gradient. The results indicate an eighty-fifth percentile speed on the flat of 22 kph, and for a downhill gradient of 3%, 25 kph. The power required to cycle has been estimated and shows that cyclists deliver around 150 W on the flat, but that this rises to around 250 W climbing hills. Mean acceleration on the flat is 0.231 m/s² and the average power output over the acceleration phase, which is of mean duration 26 s, is approximately 120 W. Air resistance accounts for approximately 70% of the resistive force when cycling at design speed.It is recommended that designers adopt 25 kph as a design speed for gradients less than 3%, but that consideration should be given to design speeds of up to 35 kph for steeper gradients. Free-flow speeds in this range should be used when modelling mode and route choices and in benefit appraisal.     

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.     

En-route weather and place valuations for different transport mode users

With the increasing societal interest in climate change, mostly separated strands of literature have investigated the travel-behavioural, thermo-sensational and environmental–psychological effects of weather on people in everyday life. This research conceptually and statistically integrates these fragmented insights. Drawing on unique Greater Rotterdam (The Netherlands) travel diary data enriched with hourly meteorological and spatial route attributes, we analyse how weather affects different transport mode users’ en-route place valuations in terms of liveliness, friendliness and aesthetics. Our main findings indicate that windy, cloudy, cold (<15 °C) or too hot (⩾25 °C) weather conditions negatively affect en-route place valuations, either directly or through lower thermal comfort. Active mode users generally value their route surroundings more positively than motorised transport modes, however they also appear more strongly affected by weather in their thermal experiences and place valuations. Policy makers are advised to expand climate-sensitive urban planning along active transport mode infrastructures.     

The effects of road infrastructure improvement on work travel in Northern Iceland

Work travel is an important alternative to out-migration in rural areas characterized by a limited range of jobs. The size of local labour markets is determined in part by geography and tradition, but advances in transportation have the potential to move people and communities closer together and transform established mindscapes. In Iceland, the dispersion of the rural population, a challenging terrain, and unpredictable weather has made road infrastructure improvements a key component in regional development strategies. A large-scale tunnel project completed in 2010 was intended to strengthen a vulnerable rural area on the northern coast and expand the urban labour market of the regional centre of Akureyri. Traffic surveys and resident surveys conducted before and after the tunnels show a substantial increase in 17–34 km work travel between rural communities. Work travel 61–77 km to and from the regional centre did however not increase. The average length of work travel has shortened but the increase in commuting yielded a net increase in total km commuted. The tunnels increased work travel irrespective of age and education, but increased work travel by women with children in the household in particular. The results suggest that large-scale road infrastructure improvements may substantially strengthen rural labour markets within a driving distance of 15–30 min, but may not extend the edge of micropolitan labour markets 45–60 min from an urban centre of less than 20 thousand inhabitants.     

Bus rapid transit impacts on land uses and land values in Seoul,Korea

Bus rapid transit (BRT) has gained popularity as a cost-effective alternative to urban rail investments; however, relatively little is known about its impacts on land-use changes and land values. This paper examines the land-market effects of converting regular bus operations to median-lane bus services in Seoul, Korea, one of the densest, most congested cities in the world. Multilevel models reveal BRT improvements prompted property owners to convert single-family residences to higher density apartments and condominiums. Land price premiums of up to 10% were estimated for residences within 300 m of BRT stops and more than 25% for retail and other non-residential uses over a smaller impact zone of 150 m. The research findings underscore the importance of introducing zoning and other land regulatory changes prior to the initiation of BRT improvements as well as applying value-capture tools to help finance investments and redress inequities.     

Cities and flows: re-asserting a relationship as fundamental as it is delicate

This paper emphasizes the relationship between cities and (transport) flows and critically explores the question of how this relationship has changed over time. It ties in with the legacy of Brian Hoyle’s work on port cities and discusses the general mechanisms and trajectories of urban development in the context of transport networks, particularly the tension between the concentration and dispersal of flows and their impact on places. Thus, the relationship between places and flows is considered both fundamental and delicate: that is, it is not only immanent to both, it also causes tensions and conflict. This is discussed in more detail in relation to two distinct cases: ports and airports. In response to related conflicts, the integration of flows in urban areas is pursued as a policy and planning strategy. However, the cases reveal that integration is difficult to achieve, due to complex systems’ dynamics and the individual logic of each sector, where integration is often accompanied by disintegration. Some light is also shed on a constructivist view of the subject matter. Finally, some ramifications for research and planning practices will be presented.     

Environmental benefits of air–rail intermodality: The example of Madrid Barajas

The environmental impact of transport is a growing issue in transport infrastructure planning. The construction of a high-speed rail station at the Madrid Barajas Airport in Spain is an example of the integration of different transportation modes, with expected environmental benefits. We construct a model to assess modal choice and environmental benefits. The results show that with high-speed rail the number of people choosing air travel and the private car is reduced leading to important environmental benefits: a reduction of close to 5 kg of CO₂ per passenger, or 10% of all emissions on the corridor. Our results also show that increasing the cost of using the private car is picked up by air transport rather than high-speed rail, leading to an increase in total emissions.     

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.