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.     

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.     

Localized competitive advantage and price reactions to entry: Full-service vs. low-cost airlines in recently liberalized emerging markets

This paper empirically investigates price reactions to the entry of the low-cost carrier Gol Airlines in the Brazilian domestic market in 2001. Given the substantial reduction in unconditional yields of the incumbent airlines on routes actually entered by Gol, we perform an econometric analysis of the determinants of pricing power along with the analysis of the pattern of price reactions by incumbent legacy carriers. Using data from a panel of routes disaggregated at the airline level, we obtain that (i) both airport and route presence are relevant at explaining pricing behavior; (ii) price responses vary significantly according to flight distance and the amount of seats supplied by the entrant, in the sense that the shorter the route, and the more the seats offered by the newcomer, the stronger the price reactions from the incumbents, with significant point estimates in the range 22–26% in yield reduction for routes as short as 350 km (approx. 195 miles). More generally, the results shed light on the impacts of airline deregulation in emerging markets and the issue of localized competitive advantage due to product differentiation in the industry.     

Impact of operational performance on air carrier cost structure: Evidence from US airlines

The impact of operational performance on airline cost structure is empirically investigated using an aggregate, statistical cost estimation approach. Two distinct sets of operational performance metrics are developed and incorporated into the airline cost models as arguments. Results from estimating a variety of airline cost models reveal that both delay and schedule buffer are important cost drivers. We also find that flight activity outside schedule windows increases cost, whereas flight inactivity within schedule windows does not. Using the estimated cost models, we predict the cost savings to airlines of “perfect” operational performance, obtaining an estimate in the range of $7.1–13.5 billion for 2007.     

Fuel burn rates of commercial passenger aircraft: variations by seat configuration and stage distance

Aircraft fuel consumption is a very large component of airline costs. Fuel burn is also very important because it is highly correlated with emissions and contributes directly to transport externalities. This paper calibrates fuel burn in kilos per seat per nautical mile for aircraft using the EMEP/EEA aircraft inventory database. We then employ the model with OAG flight schedule data to evaluate fuel burn by flight routes and aircraft types at a global scale. The paper shows comparative fuel use among different distance based markets as well as among a variety of routes in the long-haul market. The results show geographical heterogeneity of fuel burn rates among a variety of routes, while controlling for seat configuration and stage distance. The paper finds that stage lengths centered on 1500–2000 NM have the lowest fuel burn rates under current technology, fleet composition, and seat configuration. These findings, together with comments on the viability of long range flights provide better understandings not only for the carbon taxation debates but also for operational efficiency of current aviation markets. The lower rates for moderate distance flights seems to favor networks without extreme links, and supports the use of a hub connection scheme.     

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.     

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.     

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.     

Future mobility in India: Implications for energy demand and CO2 emission

The aim of this study is threefold. First, it aims to provide a reliable data set of land-based passenger traffic volumes in India from 1950–1951 to 2000–2001 for the five major motorized modes of transport—two-wheelers, cars, auto-rickshaws, buses, and railways. Second, based on this data set, it aims to estimate the long-term trends in motorized traffic volume and modal split up to the year 2020–2021. Third, based on the projected values of aggregate traffic volume and modal split, this study aims to estimate the level and growth of energy demand and CO₂ emission from the passenger transport sector in India. It is found that the motorized traffic volume in India will very nearly touch the mark of 13 000 billion passenger-kilometers in 2020–2021, out of which 91.7% will be provided by the roads and the rest by railways. If there is no reduction in modal energy and CO₂ intensities, energy demand is projected to increase from 1060.8 peta joules in 2000–2001 to 5584.4 peta joules in 2020–2021 and CO₂ emission will increase from 19.80 to 93.25 million metric tons of carbon equivalent during the same period.     

Multivariate analysis of the impacts of NAS investments: A case study of a capacity expansion at Dallas-Fort Worth Airport

Multivariate statistical analysis is used to estimate the impacts of a major capacity expansion at Dallas-Fort Worth International Airport. The model relates the Daily Flight Time Index (DFTI) to demand, weather, origin airport congestion, and the expansion itself. The effect of the capacity expansion on DFTI is found to depend strongly on visibility. On average, the index in the post-expansion period is 1.3 min less as a consequence of investment. This change includes a larger reduction in departure delay that is offset by an increase in taxi time. Moreover, the reduction caused by the expansion has been more than offset by increases in the DFTI resulting from other factors, notably increased demand and worse weather.     

Policy clash: Can projected aviation growth be reconciled with the UK Government's 60% carbon-reduction target?

In 2004, the UK's aviation industry emitted an estimated 9.8 MtC; a figure that, without direct intervention, is projected to rise to 16–21 MtC by 2030 according to the UK Government. As the UK's 60% carbon-reduction target approaches, so aviation is likely to become a dominant carbon-emitting sector. This paper calculates the proportion of carbon emissions resulting from the Government's projected aviation growth in relation to a contracting carbon budget. It concludes that the Government must urgently address today's very high levels of growth in emissions within the industry, and ensure future growth can be reconciled with the Government's own carbon targets.     

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.     

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.     

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.     

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.     

Mapping bicycle use and the risk of accidents for commuters who cycle to work in Belgium

This paper explores the spatial patterns of bicycle use for commuting and the risk cyclists run being injured in a road accident when commuting to work in Belgium. Exploratory data analyses suggest that the observed differences in the use of the bicycle to get to work are strongly linked to the urban hierarchy: commuters are more inclined to cycle in cities and specifically in regional towns (with 25 000 to 120 000 inhabitants). In large cities (more than 200 000 inhabitants), less commuting by bicycle takes place. The relationship between bicycle use and the risk of being seriously injured or killed in a road accident is also studied. A cluster analysis confirms that high proportions of commuter cyclists are correlated with low risks of becoming a casualty. It also shows that there are strong spatial differences (regional and between different types of towns) in bicycle use and the risk of an accident. This suggests that cycling policies should be spatially differentiated.     

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.     

How children view their travel behaviour: a case study from Flanders (Belgium)

Understanding the thoughts of contemporary children about travel and their opinions on different transport modes of transport may provide important answers for policy-makers on how to respond to current and future transport needs of children. Obviously, children do not act autonomously and their travel behaviours also strongly influence their parents’ travel behaviours. Therefore, a better understanding of children’s travel behaviours seems necessary.This paper reports the results of a large-scale, self-reporting survey (N = 2546) that was conducted to examine the concept and meaning of travel and travel behaviour of children aged between 10 and 13 years in Flanders. It was found that children are able to complete a travel diary on their own, that their travel patterns differ and that the most important part of travelling for them is the social aspect.     

Sea-level rise impacts on transport infrastructure: The notorious case of the coastal railway line at Dawlish,England

Future climate change is likely to increase the frequency of coastal storms and floods, with major consequences for coastal transport infrastructure. This paper assesses the extent to which projected sea-level rise is likely to impact upon the functioning of the Dawlish to Teignmouth stretch of the London to Penzance railway line, in England. Using a semi-empirical modelling approach, we identify a relationship between sea-level change and rail incidents over the last 150 years and then use model-based sea-level predictions to extrapolate this relationship into the future. We find that days with line restrictions (DLRs) look set to increase by up to 1170%, to as many as 84–120 per year, by 2100 in a high sea-level rise scenario (0.55–0.81 m). Increased costs to the railway industry deriving from maintenance and line restrictions will be small (£ millions) in comparison with damage caused by individual extreme events (£10s of millions), while the costs of diversion of the railway are higher still (£100s of millions to billions). Socio-economic costs to the region are likely to be significant although they are more difficult to estimate accurately. Finally, we explain how our methodology is applicable to vulnerable coastal transport infrastructure worldwide.