Micro-level analysis of airport delay externalities using deterministic queuing models: a case study

We analyze runway delay externalities at Los Angeles International Airport (LAX) using a deterministic queuing model. The model allows us to estimate the delay impact of each specific arriving flight on each other specific arriving flight. We find that, despite being only moderately congested (average queuing delay only 4 min per arriving flight), individual flights can generate as much as 3 aircraft-hours of external delay impact on other flights, with an average impact of 26 aircraft-minutes and 3400 seat-minutes. About 90 percent of this impact is external to the airline as well as the flight, a consequence of the lack of a dominant airline at LAX. We then compare the delay impact of each individual flight to its contribution to schedule convenience by determining the amount of “schedule delay” that would result if the flight were eliminated and its passengers forced to use the previous flight flown by the same airline from the same origin. We find that a number of commuter flights serving high density, short-haul segments generate much more queuing delay than they save in schedule delay, with the ratio exceeding 10 in several cases. We argue that social welfare would increase if such flights were eliminated, upsizing others as necessary to accommodate the displaced loads.     

Mergers and acquisitions in aviation – Management and economic perspectives on the size of airlines

This paper reviews literature and management perspectives on airline mergers and acquisitions. We find that M&A/consolidation is seen as a “game-changer” and mandatory to survive in aviation markets. We, therefore, apply DEA models to 66 airlines to evaluate whether big is indeed always beautiful. Our results suggest that the optimal airline size is between 34 and 52 bn available seat kilometre capacity and that airlines with more than 200 bn ASK are definitely too large to operate efficiently. This also applies when revenues are included in the DEA models, which is central as yield management and ancillary revenues are increasingly important.     

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.     

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

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

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.     

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.     

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.     

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.     

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.     

Airport–airline vertical relationships,their effects and regulatory policy implications

This paper examines the forms and effects of vertical relationships between airports and airlines with a focus on the North American and European aviation markets. We find that such vertical relationships enables those participating to achieve various benefits and may be formed as a competitive response to other competing airport–airline alliances. In some cases, vertical airport–airline relationships strengthen the hub status of major airports, leading to increased employment and service quality in local markets. On the other hand, preferential treatment of a particular airline by an airport may enhance that airline’s market power, allowing it to dominate the airport and charge hub premiums. The competition and welfare implications of airport–airline vertical alliances can be complicated and two-sided, subject to the influences of other factors such as the market structures of the airline and airport markets.     

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.     

Air deregulation in China and its impact on airline competition 1994–2012

China’s air transportation has experienced rapid growth and major reforms in the past three decades, some of which have been partially successful and are still ongoing today. The paper aims to analyze China’s air deregulation experience over the last two decades and its impact on airline competition from a geographical perspective. After the establishment of the “Big Three” in 2002, the paper reveals that there has been a trade-off between the extent of deregulation and airline competition in China because the central government has tended to strengthen the “Big Three” rather than totally open the market to private and locally owned airlines. The paper uses each airline group as the basic unit of analysis and reveals that (1) the air market has been more concentrated in the “Big Three” as a result of the process of air deregulation; (2) airline competition in over two thirds of the airports and one half of the routes has increased in the last 18 years, but the core airports and trunk routes are chiefly dominated by the “Big Three”. The peripheral airports and thin routes have been operated by private and locally owned airlines; and (3) regionally, airline competition has occurred in most airports of the eastern region, and it is more intense than in the central and western regions. But even here, competition in the eastern region has however decreased in 1994–2012. The three main contributions of the paper are: (1) the use of two measures of competition in the airline market; (2) the analysis of the historical evolution of competition; and (3) an understanding the role of the geography of competition in the Chinese airline market.     

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.     

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.     

Effects of upgrading to cycle highways - An analysis of demand induction,use patterns and satisfaction before and after

ObjectiveThe objective of the present study is to investigate the effects of improvements made to two large, interconnected bicycle infrastructure in the western suburbs of Copenhagen, Denmark, on bicycle volumes and mode share, and cyclists' behaviour, perceptions, and experiences.MethodsEffects are assessed by analysing data from automatic counting stations during 35 months to measure the changes in bicycle volumes on the investigated routes. Furthermore, a questionnaire survey repeated three times – before, and one and two years after opening the improved routes - is used. Findings are supported by a control survey at a nearby facility, which was not influenced by the infrastructure improvements.ResultsThe investments related to the two investigated cases of infrastructure improvements resulted in a significant increase in the volume of bicyclist two years after the improvements. On one of the routes, the “Albertslund Route”, on weekdays during the rush hour in daylight, an increase from 126 to 203 bicyclists/h was recorded, whereas an increase from 24 to 32 bicyclists/h was recorded at “Vestvolden” for the same period. Most of the increase could be attributed to relocation of bicyclists from other routes. Induced cycling trips – trips that were not previously made by bicycle - were estimated to account for only 4–5% of the bicyclists two years after improvements. Bicyclists using the improved route express an increase in satisfaction with the quality of the facilities, which is significantly higher than at the control site.ConclusionData from the counting stations provides useful information if measured over a long period. This is necessary to correct for factors such as climate effects and temporal variation. Investments in cycle infrastructure in the investigated case led to a higher number of bicyclists who were mainly relocated from other routes. A minor increase in the modal share of cyclists was observed two years after the infrastructure improvements. Furthermore, the investments resulted in a higher degree of satisfaction among active bicyclists. If measured over a longer period, this could lead to a higher modal share due to a potential social advertising effect.     

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

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

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.     

School site walkability and active school transport – association,mediation and moderation

Increasing active school transport (AST) can improve population health, but its association with the urban form is not fully clear. This study investigated the association of an objective school walkability index with AST and how this association is mediated by the perceived physical and social environment. 1250 Danish students aged 11–13 years completed a commuting diary and a questionnaire. The walkability index was constituted of measures of road connectivity, traffic exposure and residential density. AST’s share in all school trips was 85.4% with little difference between genders. The school walkability index was significantly associated with AST (Medium vs. Low OR 2.68; High vs. Low OR 2.49). Adding the perceived physical and social environment variables improved the model prediction of AST, with no change in the association with the school walkability index. Furthermore, distance to school significantly moderated the association between the school walkability index and AST. This research confirms the association between the urban form surrounding schools and AST. Medium and highly walkable school sites in combination with a distance to school below 2 km, no speeding traffic and many paths in the neighborhood was associated with the highest odds ratio for AST.     

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.     

Individuals' social preferences in joint activity location choice: A negotiation model and empirical evidence

Out-of-home leisure activities are often conducted jointly by individuals implying that location and travel choices made for these activities are the result of a group interaction. Current utility-theoretic approaches assume an aggregated group utility function and hence ignore aspects of the group decision making process. In this study, an empirical model of joint-activity choice is developed that, in contrast, assumes a negotiation process. A social utility function describes how individuals deal with preference differences in the group. The model is estimated based on an experimental activity-travel choice task where group settings are mimicked. A sample (N = 315) from a national panel of individuals participated in the experiment. Estimation results based on a discrete mixture model show that individuals display a preference for locations in which losses are equally distributed in the group even when this comes at the costs of the total group outcome. Results further show that the social utility function is asymmetric: compromise solutions are favored more strongly when consequences relate to costs (travel costs) than when they concern rewards (attractiveness). Furthermore, there is considerable heterogeneity in how people make social trade-offs. It is concluded that the model offers new insights in location preferences for joint activities that should be taken into account in spatial choice models and accessibility analysis.