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.     

Policy integration: What will it take to achieve more sustainable transport solutions in cities?

There has been a rhetorical shift in paradigm from predict and provide for road transport to one which addresses sustainable mobilities. This paper explores the organizational and institutional issues of policy integration and the implementation mechanisms which could bring about a sustainable transport system predicated on the reduction of CO₂ emissions and non-renewable resource use and which produces more socially equitable outcomes. The paper first outlines the English policy context in terms of responsibilities, powers and resources available to local transport planners, and identifies the tools of government that can be more efficiently applied to effect a more sustainable transport system which specifically reduces CO₂ emissions. A snapshot of transport decision-making in five local transport authorities in England is presented, using a case study methodology, which explores the joint working practices of practitioners in five public policy sectors that influence accessibility patterns. The case study highlights the norms and values of the local public administrators who affect local transport mobility and how they in turn are hindered both by the rigidity of central government direction and an insufficiency of implementation tools.     

How could the station-based bike sharing system and the free-floating bike sharing system be coordinated?

The station-based bike sharing system (SBBSS) and the free-floating bike sharing system (FFBSS) have been adopted on a large scale in China. However, the overlap between the services provided by these two systems often makes bike sharing inefficient. By comparing the factors that affect the usage of the two systems, this paper aims to propose appropriate strategies to promote their coordinated development. Using data collected in Nanjing, a predictive model is built to determine which system is more suitable at a given location. The influences of infrastructure, demand distribution, and land use attributes at the station level are examined via the support vector machine (SVM) approach. Our results show that the SBBSS tends to be favored in areas where there is a high concentration of travel demand, and close proximity to metro stations and commercial properties, whereas locations with a higher density of major roads and residential properties are associated with more frequent use of the FFBSS. With regard to the methods used, a comparison of several machine learning approaches shows that the SVM has the best predictive performance. Our findings could be used to help policy makers and transportation planners to optimize the deployment and redistribution of docked and dockless bikes.     

The Multi-Actor Multi-Criteria Analysis (MAMCA) application in the Flemish long-term decision making process on mobility and logistics

The Multi-Actor Multi-Criteria Analysis (MAMCA) is a methodology to evaluate different policy measures whereby different stakeholders’ opinions are explicitly taken into account. This paper describes the MAMCA methodology and how it has been used in the “Flanders in Action Process”. One of the objectives of this process is to turn Flanders into a top region in terms of mobility and logistics by attracting logistic activities with a large added value, realizing fluent and widely accessible mobility, a huge increase in traffic safety and a decrease of the environmental impact of transport. As there are a wide range of actors with different interests involved in this process, the MAMCA methodology was applied to evaluate a set of possible policy measures being proposed to reach this objective. An important advantage of this methodology is that it is able to support the decision maker in his final decision as the inclusion of different points of view leads to a general prioritisation of the proposed policy measures.     

Built environment,peak hours and route choice efficiency: An investigation of commuting efficiency using GPS data

Commuting efficiency measures the impact of commuting on urban spatial and social environments. Urban policies aim to reduce commuting distances and improve commuting efficiency by supporting mixed land-use and job-housing balance. Many studies have addressed these issues by examining excess commuting at the aggregate level, and most aggregated measurements of excess commuting are based on home-to-work commuting flows between zones. However, residents' travel behaviour does not consist solely of rational attempts at minimizing commuting distances but is instead affected by commuting hours, the complexity of the commuting chain and the built environment. Thus, commuting efficiency must be studied at the individual or disaggregated levels. This paper examined individual commuting efficiency in suburban Beijing using a GPS-facilitated activity-travel survey and investigated the differences in commuting distance and route choice efficiency between morning and evening peaks. Notably, in so doing, we considered non-work stops, and also explored the impact of urban spatial factors – in both residential and working areas – on commuting efficiency using multilevel mixed effects generalized linear models. The findings suggest that there are significant differences in commuting distance and commuting efficiency between morning and evening peaks based on the nature of commutes. Residents working in city centres or with jobs near railway stations, with higher road network densities or with lower facility densities seem to be more adept at selecting optimal routes.     

Shortest path or anchor-based route choice: a large-scale empirical analysis of minicab routing in London

Understanding and modelling route choice behaviour is central to predicting the formation and propagation of urban road congestion. Yet within conventional literature disagreements persist around the nature of route choice behaviour, and how it should be modelled. In this paper, both the shortest path and anchor-based perspectives on route choice behaviour are explored through an empirical analysis of nearly 700,000 minicab routes across London, United Kingdom. In the first set of analyses, the degree of similarity between observed routes and possible shortest paths is established. Shortest paths demonstrate poor performance in predicting both observed route choice and characteristics. The second stage of analysis explores the influence of specific urban features, named anchors, in route choice. These analyses show that certain features attract more route choices than would be expected were individuals choosing route based on cost minimisation alone. Instead, the results indicate that major urban features form the basis of route choice planning – being selected disproportionately more often, and causing asymmetry in route choice volumes by direction of travel. At a finer scale, decisions made at minor road features are furthermore demonstrated to influence routing patterns. The results indicate a need to revisit the basis of how routes are modelled, shifting from the shortest path perspective to a mechanism structured around urban features. In concluding, the main trends are synthesised within an initial framework for route choice modelling, and presents potential extensions of this research.     

Looking over the horizon: Transport and reduced CO2 emissions in the UK by 2030

Transport is a major user of carbon-based fuels, and achievement of the targets set at the Kyoto Protocol and elsewhere means that the EU and national governments must reduce CO₂ emissions in all sectors, including transport. This paper reports on a recently completed study for the UK government on the options available to meet a 60% CO₂ reduction target by 2030 in the UK transport sector. The study follows a backcasting study approach, developing a business as usual baseline for transport emissions, and two alternative scenarios to 2030. Different policy measures are assessed and assembled into mutually supporting policy packages (PP). Although 2030 seems a long way ahead, action must be taken now if the targets for CO₂ reduction are to be met. The achievement of a carbon-efficient transport future, combined with holding travel levels at present levels, is likely to be very difficult. A major transformation in the way transport and urban planning is carried out is required. As transport and urban planners, we need to think very differently in tackling the new environmental and liveability imperative.     

Improving Bus Service Levels and social equity through bus frequency modelling

Bus lines play an essential role in providing urban public transport service. Demographic and socioeconomic characteristics determine the specific transport service needs of districts that, in most cases, are not served by the existing bus routes. Small changes in the frequency of a bus route can have a direct effect on the territorial distribution of a city's public transport service. Adjusting the frequencies of a bus fleet can help planners improve the service level and adapt the fleet's spatial distribution. A bus frequency optimization methodology is proposed to improve harmonization between service level and social equity in public transport. The method relies on a simple spreadsheet that integrates geographic data about bus routes and socioeconomic information about city districts. Simulation and optimization procedures are coordinated to appropriately adjust the routes to the geographic space. The proposed method is tested in a real case study that demonstrates its usefulness in analysing the service level and equity of a transport system and improving a city's public transport planning.     

A novel origin destination based transit supply index: Exploiting the opportunities with big transit data

Quantifying transit resources and its networkwide temporal distribution is needed for the informed transit planning and operations decisions. One effective way to estimate the transit resource provision to a zone is to calculate the transit supply index. However, in literature, Supply Index (SI) is modelled considering the transit services allocated to a zone and ignores the quality and quantity of the supply provided between two zones. Addressing this need, this paper proposes a novel origin-destination based supply index (odSI) that incorporates a) zonal characteristics such as transit routes operate in origin zone, number of trips made by those routes, walk buffer areas of transit stops, and the total area of the zone; b) the quality of the service provided in terms of the average speed and route straightness ratio; and c) origin-destination dependent variables such as the minimum number of transfers needed to travel between two zones, the average transit speed between those zones, straightness of transit routes, and total available capacity. As proof of concept, the proposed odSI model is applied on the real network from Brisbane, Australia, at Statistical Area-2 level. The odSI results for 136 × 136 zonal pairs are presented for four different time periods (two peak and two off-peak periods). Furthermore, detailed analysis is carried for a zone, Grange, as an origin and the remaining 135 zones as destinations. The applicability of the proposed odSI model on Brisbane demonstrates its capability to provide valuable insights for an extensive network, which can help planners visualise and improve the complex and cumbersome networks in a more effective manner.     

The formulation and evaluation of transport route planning alternatives: a spatial decision support system for the Via Baltica project,Poland

Transport planning plays an undeniably key role in the economic growth of any region. However, when done heedlessly this planning can be detrimental to the biophysical and social environment of the region. In transport route planning generally one or a few alternative routes are proposed, usually representing the interest of the proponent. If required, an environmental impact assessment is carried out on these alternatives. Although, EIA and SEA are meant to be effective in taking informed decisions about the proposed route, these alternatives – the heart of impact assessment – are themselves devised in a subjective and non-spatial manner.Such an approach may easily overlook routes, which could otherwise have been more suitable. A planning system that directly takes into account environmental and socio-economic considerations in selecting alternative routes facilitates sustainable development. This paper presents a holistic and coherent spatial multi-criteria network analysis method for the generation of optimal routing alternatives under different policy visions, in a network of existing roads.The presented methodology was case-tested for the highly contested 340 km portion of the Via Baltica corridor in Poland, a part of the trans-European transport network (TEN-T) program. The methodology shows its ability to serve as a versatile effect-based decision support system for transport route planning at a strategically higher level of planning, particularly for (geographically) large-scale investment schemes.     

Land use change along Denver's I-225 beltway

This paper examines the long-term impact of suburban Denver's I-225 beltway on surrounding land uses following its introduction into a relatively undeveloped area. Analysis of residential, commercial, and office uses indicates that while the beltway did not serve as a catalyst for large-scale development, there was a gradual reorientation with higher residential and commercial densities along the route. Office densities were less affected by the immediate access provided by the route. Land use development occurred in three stages: (1) penetration of residential development into the corridor with little commercial or office development; (2) proliferation of residential development and penetration of commercial and office activities; (3) proliferation of commercial and office development and reorientation toward beltway.     

Neighborhood walking densities: A multivariate analysis in Halifax,Canada

Neighborhood walkability is important to planners and policy makers in the public health, land use planning, and transportation fields. This research contributes to knowledge of walking behaviour by aggregating GPS-tracked walking trips as neighborhood walking densities, and investigating local characteristics affecting those densities. The study maps walking trips in urban and suburban neighborhoods of Halifax, Canada, using data from the Space-Time Activity Research (STAR) survey conducted in 2007–2008. Respondents completed a two-day time-diary, and their movements were tracked using a GPS data logger. The 1971 primary respondents recorded 5005 geo-referenced walking trips.From mapped walking tracks, walking distances were aggregated to 87 census tracts, and expressed as walking densities (per resident, per meter of road, and per developed area). Multivariate regression was used to examine which neighborhood variables and socio-demographic controls are most useful as estimators of walking densities. Contrary to much of the walkability literature, built-environment measures of road connectivity and dwelling density were found to have little estimating power. Rather, retail lot coverage ratio was the single most useful estimator, acting as a proxy to identify traditional retail shopping streets. Office and institutional land uses were also important contributory estimators (highlighting areas of dense employment), as were measures of residents' income and age.     

A GPS data-based analysis of built environment influences on bicyclist route preferences

This study examines the effects of built environment features, including factors of land use and road network, on bicyclists' route preferences using the data from the city of Seattle. The bicycle routes are identified using a GPS dataset collected from a smartphone application named “CycleTracks.” The route choice set is generated using the labeling route approach, and the cost functions of route alternatives are based on principal component analyses. Then, two mixed logit models, focusing on random parameters and alternative-specific coefficients, respectively, are estimated to examine bicyclists' route choice. The major findings of this study are as follows: (1) the bicycle route choice involves the joint consideration of convenience, safety, and leisure; (2) most bicyclists prefer to cycle on shorter, flat, and well-planned bicycle facilities with slow road traffic; (3) some bicyclists prefer routes surrounded by mixed land use; (4) some bicyclists favor routes which are planted with street trees or installed with street lights; and (5) some bicyclists prefer routes along with city features. This analysis provides valuable insights into how well-planned land use and road network can facilitate efficient, safe, and enjoyable bicycling.     

Route choice of bike share users: Leveraging GPS data to derive choice sets

To identify the determinants of bike share users' route choices, this research collects 132,397 hub-to-hub global positioning system (GPS) trajectories over a 12-month period between April 1, 2015 and March 31, 2016 from 750 bicycles provided by Hamilton Bike Share (HBS). A GIS-based map-matching algorithm is used to derive users' routes along the cycling network within Hamilton, Ontario and generate multiple attributes for each route, such as route distance, route directness, average distance between intersections, and the number of turns, intersections, and unique road segments. Concerning route choice analysis, the origin and destination pair should be the same for all routes within a choice set, thus HBS users' trips are grouped by origin-destination hub pairs. Since trips taken by different users between a hub pair can follow the same route, unique routes are extracted using a link signature extraction tool. Following this, a normalized Gini (G_n) coefficient is calculated for each hub pair to evaluate users' preferences among all the unique hub-to-hub route choices. A G_n closer to 0 indicates that routes between a hub pair are more evenly used, while a value closer to 1 implies a higher preference toward one dominant route. Three route choice models, a global model, a medium G_n model, and a high G_n model, are estimated using Path-Size Logit to determine how route choice is affected by the presence of dominant routes. These models suggest that HBS users are willing to detour for some attributes, such as bicycle facilities, but tend to avoid circuitous routes, turns, steep slopes, and roads with high traffic volume.     

An analysis of drivers route choice behaviour using GPS data and optimal alternatives

This work aims to study drivers' route choices using a dataset of low frequency GPS coordinates to identify travels' trajectories. The sample consists of 89 drivers who performed 42 thousand paths in the province of Reggio Emilia, in Italy, during the seventeen considered months. Four attributes that may be important for the driver are identified and four optimal alternative paths are created based on the selected objectives to evaluate route choice behaviour. The comparison between the characteristics of the paths allows to conclude that drivers select routes that are overall longer than their optimal alternatives but that allow for higher speeds. Furthermore the statistical analysis of drivers' route choices in macroareas evidences that drivers have different behaviours depending on the geography of the territory. Specifically, there is higher heterogeneity of route choices in the plain areas compared to the mountains. In the second part of this work, clusters of repetitive travels are identified and a Geographical Route Directness Index is proposed to identify the areas of the province where the deviation from the shortest alternative path is higher. The analysis shows that, among groups of repetitive travels, the value of the index is higher along the ring road of the city of Reggio Emilia and there is a strong negative correlation between the frequency the driver selects the longer alternative that allow for higher speed, and the number of additional kilometres the same driver has to travel.     

Mutual influence across routes using a common airport: The case of the domestic market in Japan

This paper empirically investigates the mutual influence of traffic volumes across routes serving the same airport. Regression analysis using the data on Japan's domestic air transport market reveals that an increase in passengers on a given route has a positive effect on the number of passengers on other routes that share an endpoint airport with the given route. This result implies that a change in policy for an airport is likely to influence routes that do not serve that airport as well as the routes that do.     

Examining spatial variations in minimum residential parking requirements in Melbourne

Minimum off-street residential parking requirements are used in many cities as a way to accommodate parking demand associated with new residential development. In some cases, variations to these requirements are used in the form of reduced (or eliminated) minimums and/or maximum parking requirements to more actively manage parking demand. This paper assesses how such variations affecting new residential apartment development in Melbourne, known locally as parking overlays, compare against residential parking demand. Using household car ownership data as a proxy for off-street residential parking demand, a case-control analysis was undertaken to compare car ownership within and immediately outside areas affected by the parking overlays, while controlling for a range of built environment, public transport, demand management and socio-demographic variables. Key findings indicate that car ownership is generally lower in areas affected by parking overlays, yet this was either roughly the same or well below the actual parking requirement. Through regression modelling, the results highlighted the importance of public transport service quality, car parking requirements and demographics in influencing car ownership within and immediately outside the parking overlay areas. These results were used to develop a parking overlay index to identify other areas that could benefit from more flexible residential parking requirements. Despite parking overlays considered as a form of parking management, the results imply that, in Melbourne, they represent little more than a conventional supply-side approach to parking policy. The results indicate that residential off-street parking requirements could be reduced further in Melbourne, both within and outside of areas affected by parking overlays, to more actively manage parking demand.     

The cost of aircraft noise – Does it differ from road noise? A meta-analysis

This paper aims at studying the difference in cost between aircraft noise and road noise using meta-analysis. 90 NDI estimates have been gathered from the literature (a total of 53 studies), out of which 44 are estimates for aircraft noise and 46 are for road noise. The results of the meta-regression suggest that aircraft noise costs somewhere in the range of 0.40 and 0.60 percent more per increased dB than road noise. Knowing the associations between these costs of noise pollution can be a convenient tool for planners and policy makers, offering an opportunity to make predictions of aircraft noise when only estimates of road noise are available, and vice versa.     

Understanding bus rapid transit route ridership drivers: An empirical study of Australian BRT systems

Bus Rapid Transit (BRT) systems are an increasingly popular public transport option internationally. They provide rail-like quality for bus services for a fraction of the cost of fixed rail. Many claims of high and increasing ridership have resulted from BRT system development; however, it is unclear exactly which aspects of BRT system design drive this. This paper explores whether BRT design features, among other influences, significantly increase ridership above and beyond the impact of service levels. It does so using a series of regression models undertaken on 77 BRT and non-BRT bus routes in Australia which is known for its diversity in BRT route design. Explanatory variables used included service level, frequency, speed, stop spacing, share of segregated right of way, vehicle accessibility, employment and residential density, car ownership levels and BRT infrastructure quality. Five models explored the role of these variables. Two models found that service level dominates predictions of boardings per route km although they suffer from endogeneity. Further models control for this influence by modelling boardings per vehicle km. Overall results suggest that some BRT infrastructure treatments such as right of way have a significant impact on ridership but the influence of infrastructure is within the context of high service levels. The role of accessible vehicles has also been highlighted in this research, although more research is needed to clarify this influence. The paper concludes with a discussion of the various influences on ridership and recommendations for existing policy and future research.     

The rail transit system and land use change in the Denver metro region

One of the goals of constructing and operating an extensive rail transit system in the Denver metro region since 1994 has been growth and development of land use along the rail transit system. This paper analyzes the trend of land use growth and development around the rail transit system mostly from 2000 to 2010. Primarily land parcel data collected from the assessor's office of several counties in the metro region have been used to determine change in the amount of different types of land use namely commercial, mixed, industrial, multi-family residential and single-family residential near and far from the rail transit system. Change has been analyzed in terms of total square footage of the building areas as well as land use density. Statistical significance tests (Wilcoxon/Kruskal–Wallis test) have been conducted to understand if the amount of change taking place near the rail transit system is greater than away from the system. The growth of commercial land use was significantly higher near the rail transit system. More growth in multi-family residential land use has also occurred near the rail transit system, but was not significantly greater than areas away from the system. Single-family residential land use has noticeably increased in places away from the rail transit system. The other types of land use have not shown any consistent pattern in their growth either near or away from the system. Overall, a noticeable amount of land use change, especially commercial land use, has taken place around the rail transit system from 2000 to 2010. However, this change in land use cannot necessarily be attributed to the construction and operation of the rail transit system. Other factors may have influenced the growth of land use around the rail transit system more than the presence of the rail transit system itself.