Planning for sustainable accessibility: The implementation challenge

The ‘Network City’ planning strategy espouses sustainable accessibility. The aim is to re-orient the existing urban structure by focussing development at places with high accessibility in order to support an effective public and private transport system. The implementation phase calls for changes to planning practices: the need for public transport planning and development change to be mutually supportive; the need for road network planning and road design to place land use-transport integration as the core objective rather than traffic efficiency and for the need to stage development according to planned population and employment targets. This must take place within a new participatory approach. All this requires planners to gain new skills. To achieve this the system of planning must remain strong.     

Why we fail to reduce urban road traffic volumes: Does it matter how planners frame the problem?

If the objective of reducing urban road traffic volumes and GHG emissions from traffic is to be achieved, the way in which land use and transport systems in cities are planned and developed needs to change. Despite apparent agreement that this should be done and how it could be done, cities continue to be planned and developed in ways that cause and allow growth in urban road traffic volumes. In this paper we ask how planners frame the ‘transport problem’, and how their framing of the problem affects urban planning, the resulting plans and developments and the urban road traffic volumes. The discussions are based on findings from a case study, a survey and interviews with planning practitioners.     

Estimating annual average daily traffic and transport emissions for a national road network: A bottom-up methodology for both nationally-aggregated and spatially-disaggregated results

The regular and robust collection of traffic data for the entire road network in a given country will usually require high-cost investment in traffic surveys and automated traffic counters. This paper provides an alternative and low-cost approach for estimating annual average daily traffic values (AADTs) and the associated transport emissions for all road segments in a country. This is achieved by parsing and processing commonly available information from existing geographical data, census data, traffic data and vehicle fleet data. Ceteris paribus, we find that our annual average daily traffic estimation based on a neural network performs better than traditional regression models, and that the outcomes of our aggregated bottom-up road segment emission estimations are close to the outcomes from top-down models based on total energy consumption in transport. The developed approach can serve as a means of reliably estimating and verifying national road transport emissions, as well as offering a robust means of spatially analysing road transport activity and emissions, so as to support spatial emission inventory compilations, compliance with international environmental agreements, transport simulation modelling and transport planning.     

Considerations in the diffusion of a public traffic app for Metro Manila

The proliferation of apps enabling motorists to access traffic information on the move introduces several intriguing possibilities for transportation authorities. In the expectation that public demand for these apps will increase as both road traffic and smartphone ownership rise, these tools invite consideration alongside other traffic management tools. Traffic app-specific considerations include increased motorist interactivity, consumer technology diffusion, and institutional factors affecting the rollout of e-government initiatives. This article uses the introduction of the MMDA Traffic Navigator—a Manila-based, publicly developed traffic app—to illustrate these considerations. Additionally, app usage among residents of nearby cities constituting Manila’s extended metropolitan region is considered. These considerations are subsequently classified using a 4E framework under economy, effectiveness, efficiency, and equity to inform other authorities’ efforts to either incorporate traffic apps into overall transport planning or even take the initiative in developing them.     

Safety and travel time in cost-benefit analysis: A sensitivity analysis for North Rhine-Westphalia

Decisions on large-scale infrastructure concepts are frequently based on cost benefit analysis (CBA). Using 431 road projects evaluated in the integrated transport planning process in North Rhine-Westphalia, Germany (IGVP NRW) this paper examines the evaluation dimensions traffic safety (fatalities) and travel time in private passenger transport. The unit values of traffic fatalities and travel time are varied, and the effects of the variations on the rank order of the projects are examined. Target conflicts between safety and travel time are studied as well as the contribution of these two dimensions to the total benefit values. The sensitivity analysis shows that the evaluation results are fairly stable against variations in unit values of travel time and fatalities. The relevance of traffic safety in terms of its contribution to total benefit as well as in terms of the unit value appears to be relatively minor. The unit value of travel time is higher than that of lifetime. Some projects turn out as feasible in the evaluation even though they are likely to increase the number of fatalities. The paper therefore suggests the higher weighting of traffic safety in CBA.     

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

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

Willingness to spend and road pricing rates

Using a theoretical model of urban transport system the paper examines the influence of distribution of willingness to spend within the urban population on road pricing rates. It shows that the rates that must be imposed in an urban area in order to maintain pollutant concentration and congestion due to traffic within acceptable levels is heavily dependent on the distribution of the urban population’s willingness to spend. This fact severely limits the reliability of any method for calculating road pricing rates based on theoretical analysis, so that an experimental approach seems necessary. The paper shows that a relation exists between the toll rate per kilometer of trip and the average traffic congestion, which is typical of each urban area and can be determined experimentally by successively imposing three different rates and measuring the corresponding congestion levels. The relation can then be used to determine the pricing scheme when the purpose of road pricing is to maintain both the congestion and the environmental effects due to urban traffic below acceptable thresholds. An example shows how the model can help policymakers in decision-making processes.     

The development of a benchmarking tool for monitoring progress towards sustainable transportation in New Zealand

Creating and maintaining a safe and sustainable transport system is a common challenge for road authorities around the world. The New Zealand government has taken this challenge one step further by incorporating it into country’s legislation. As a consequence all road land transport authorities are committed to implementing initiatives to respond to both the challenge and the legislation. A benchmarking process for the transport sector is one of these initiatives on a national level. Benchmarking is a well known and utilised technology for the measuring of performance for infrastructure, for example within the water provision sector in England. This paper presents the development of a national benchmarking process for the transport sector of New Zealand. This development is part of a strategy to encourage road land transport authorities to improve the performance of transport in achieving sustainability and environmental targets. The development involved a literature review, proof of concept and the full implementation stage. A total of nine key performance indicators were developed to indicate the status of transport sector performance. The project and its outcomes are considered to be of benefit to road land transport authorities across the world who wish to develop a benchmark process of their own.     

A multi-criteria analysis framework including environmental and health impacts for evaluating traffic calming measures at the road network level

Recent interests in both vehicle emissions and public health have facilitated the development of more eco-friendly transportation systems. This study developed a multi-criteria evaluation framework to evaluate the effectiveness of traffic calming measures (TCMs) from the various perspectives at the road network level; operational efficiency, traffic safety, environmental and health impacts. The proposed methodology employs four-step sequential simulation experiments, including driving, traffic flow, emissions, and air dispersion simulations. The results obtained from these four simulations are used to evaluate the effectiveness in terms of safety and operational efficiency in addition to environmental and health impacts. A multi-criteria value function based on the weights estimated from the analysis of an analytical hierarchy process (AHP) is applied in the evaluation framework. As an application, chicanes and speed humps widely implemented in Korean school zones were evaluated at the road network level. The proposed simulation-based approach is expected to be effectively used for the decision-making process in selecting better alternatives for TCM.     

Road traffic noise in Montreal and environmental equity: What is the situation for the most vulnerable population groups?

Road traffic noise is one of the most detrimental environmental nuisances for the population. Prolonged exposure to high road noise levels can lead to various problems in people's health and well-being. The objective of this article is to determine whether the groups most vulnerable to road noise, that is, children under 15 years old, people 65 years old and over, and the groups most likely to experience high nuisance levels, visible minorities and low-income individuals, are affected by an environmental inequity related to this nuisance. The method of estimating this nuisance employed in the study is based on a combination of several elements: that is, average traffic flows, road geometries, normal atmospheric conditions, and the characteristics of the urban environment. All of these parameters were considered for the 14 boroughs that make up the central portion of the Island of Montreal. Modelling was used to calculate the maximum daily road noise, based in part on the LimA software predictive model and according to the XPS 31-133 computation method. The results obtained from three different statistical tests and spatial regression analyses show that, on the one hand, the groups chosen on the basis of age are not affected by any environmental inequity related to the phenomenon of road traffic noise. On the other hand, low-income individuals and visible minorities live in city blocks marked by road traffic noise levels that are slightly higher than those experienced by the rest of the population.     

The interplay of formal and informal institutions between local and regional authorities when creating well-functioning public transport systems

This paper analyzes how public transport planning is managed in institutional contexts where governance is spread across local and regional scales. The paper sheds light on two facets of the relationship between local and regional government: first, the decision-making process regarding where to provide public transport services and at what level, and second, integration of public transport with land use planning. An analytical matrix is used to cross-reference the roles of formal institutions (governance established in law) and informal institutions (governance not established in law) against local and regional responsibilities for public transport and land use. Analysis of the interplay between these three axes (formal/informal, local/regional, public transport/land use) reveals how informal institutions help regional and local authorities to negotiate the constraints of formal, statutory institutions and help to “oil the wheels” of delivering measures and policies that make public transport work as a well-functioning system. However, informal institutions clearly have their limits, in the paper exemplified by the remaining challenges to integrate regional public transport and local land use planning. An identified challenge is that, by their very nature, informal institutions are difficult to influence or modify, therefore relying on them to fill gaps in formal institutional responsibilities may be a risky strategy when unpopular decisions are made.     

Annual average daily traffic estimation in England and Wales: An application of clustering and regression modelling

Collection of Annual Average Daily Traffic (AADT) is of major importance for a number of applications in road transport urban and environmental studies. However, traffic measurements are undertaken only for a part of the road network with minor roads usually excluded. This paper suggests a methodology to estimate AADT in England and Wales applicable across the full road network, so that traffic for both major and minor roads can be approximated. This is achieved by consolidating clustering and regression modelling and using a comprehensive set of variables related to roadway, socioeconomic and land use characteristics. The methodological output reveals traffic patterns across urban and rural areas as well as produces accurate results for all road classes. Support Vector Regression (SVR) and Random Forest (RF) are found to outperform the traditional Linear Regression, although the findings suggest that data clustering is key for significant reduction in prediction errors.     

The effects of area-wide road speed and curvature on traffic casualties in England

Transport provides a range of benefits to society in terms of mobility, access and economic growth. There are however negative impacts of transport, not least in terms of environmental degradation, damage to property, traffic accidents and loss of life. This paper focuses on road traffic accidents, the reduction of which is an important aim of transport policy world wide. The primary objective of this paper is to develop a series of relationships using spatially disaggregated area-level cross-sectional data between different traffic casualties, road traffic speed and road curvature by controlling for other contributing factors associated with area characteristics. The spatial units of the analysis are the 8019 census wards in England. Ward-level casualty data are disaggregated by severity of the casualty (such as fatalities, serious injuries and slight injuries) and by the severity of the casualty related to various road users.The results suggest that increased average speed within a ward is positively associated with total fatalities and serious injuries; and road curvature is found to be negatively associated with road accidents.     

GIS-based highway maintenance prioritization model: an integrated approach for highway maintenance in Nepal mountains

Roadside slope failures often result in day to week-long traffic disruption and are a major problem in Nepal so that timely maintenance of roadside slopes needs greater priority for smooth operation of traffic. In this paper, we develop a Geographic Information Systems (GIS)-based maintenance model considering pavement and roadside slope stability conditions. A pavement maintenance priority map is prepared based on pavement condition. International Roughness Index (IRI) is used as the pavement condition index. Similarly, a roadside slope maintenance priority map is produced by analyzing slope stability condition. An integrated maintenance priority map is produced by combining both pavement and roadside slope maintenance priority maps with consideration of weighting of each maintenance component. The integrated maintenance priority index developed in the research lies from 1 to 3, and is distributed heterogeneously. Higher index values qualify for higher priority in maintenance planning. Thus, a conventional method of maintenance planning under the constraints of budget, time and resources can be improved by incorporating the actual condition of pavement and roadside slope failure susceptibility, which has the potential to improve significantly the serviceability of the road system. The study shows that GIS, which can manage and visualize different types of data together or separately, can help the decision making process for road maintenance planning in the Himalayan regions.     

Decomposing the decoupling of Danish road freight traffic growth and economic growth

In recent years many European countries have seen a decoupling of the growth in road freight traffic (vehicle kilometres) from economic growth. A similar decoupling has not been observed in road freight transport (tonne kilometres). In this paper the historical growth in national Danish road freight traffic and transport is attributed to causes using a Divisia index decomposition method. It is demonstrated that overall road freight traffic growth is a consequence of often opposite pointing growth effects in the underlying factors. The observed decoupling of road freight traffic growth from economic growth is mainly the result of use of larger vehicles, increasing average loads, and less empty running. Growth in road freight transport is primarily caused by growth in production. A decrease in the number of tons lifted per tonne produced (the handling factor) is offset by an increase in the tonne kilometres per tonne lifted.     

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.     

Key factors for successful leisure and tourism public transport provision

In the second half of the 20th century, the main focus of transport policy and transport studies was on the reduction of the use of motorised, individual transport, in particular with regard to daily commuter traffic. The main concepts concentrated on creating an attractive public transport supply and, where possible, improving the infrastructure for non-motorized traffic in order to open up alternative forms of travel. Although these concepts produced noticeable effects on everyday travel, they could not cope with steadily rising problems in the field of leisure traffic. Therefore, primarily supply oriented, autocratic desktop transport policies cannot be seen as a promising approach within the leisure context.Consequently, the article focuses on the necessary key factors for successful leisure and tourism public transport provision. It stresses the need for rethinking transport policy by choosing a demand oriented approach and realising the importance of additional accompanying efforts in the areas of marketing, transparency and quality. Focusing on the demand side, with its individual attitudes and preferences, leads to a new understanding of traffic planning by adopting a bottom up, rather than a top down approach.     

Research challenges in modelling urban road pricing: An overview

This article introduces the contributions of this special issue on modelling of urban road pricing and its implementation. The issue focuses on the design of urban road pricing schemes, and their spatial and temporal impacts, using quantitative transport (and land use) models. The policy implications of road pricing, including welfare and equity aspects, are studied for Paris, Brussels and Oslo using state of the art planning models. The issue is completed with a study of public acceptability and the upcoming road-pricing trial in Stockholm, and a review paper on the history of thought and future prospects of road pricing.     

Planning for an unpredictable future: Transport in Great Britain in 2030

This paper describes a research study, which explores alternative future scenarios for Great Britain in the year 2030 and the implications these have for travel demand and transport provision. Five alternative future scenarios are represented in the GB national transport model and forecasts are obtained for trip making, traffic levels, congestion and emissions in 2030. For all scenarios it is expected that there will be significant traffic growth. Traffic growth is restricted most in scenarios including distance-based road charging on motorways and trunk roads. However, congestion and carbon dioxide emissions are most effectively limited in scenarios with congestion-based road charging, major improvements to urban public transport and investment in new fuel technologies and in improving engine efficiency.     

Urban transport justice

Many cities in the world seek to establish more sustainable urban transport systems with a view to reduce accidents, congestion, air and noise pollution, and to improve social interactions, liveability and amenity values. Against this background, this paper frames urban transportation as an issue of justice: contemporary transport systems are characterized by injustice, as they tend to favour and prioritize motorized transport, accepting that considerable environmental and social burdens are put on more sustainable forms of transportation, other traffic participants and society as a whole. To conceptualize ‘urban transport justice’, the paper discusses three dimensions where injustices are apparent: Exposure to traffic risks and pollutants; distribution of space; and valuation of transport time. It is argued that public and political recognition of urban transport injustices provides significant argument for changes in urban planning, transport infrastructure development and traffic management.