Coordinated aviation network resource allocation under uncertainty

Congestion in the air traffic system, both recurrent and non-recurrent, is typically handled by rationing access rights to individual resources such as airports or important parts of the airspace. Under the planning paradigm employed in the US, this rationing process occurs independently at each resource. The stochastic integer programming model proposed in this paper brings coordination to this process while considering capacity uncertainty. Results of a case study suggest that the model is tractable, and generates capacity allocations that improve efficiency and enable greater responsiveness to changing capacity conditions.     

A hybrid implementation mechanism of tradable network permits system which obviates path enumeration: An auction mechanism with day-to-day capacity control

Akamatsu, 2007a, Akamatsu, 2007b proposed a new dynamic traffic congestion control scheme called tradable network permits, and demonstrated its efficiency properties for general road networks. To implement tradable permit markets, this paper proposes a novel auction mechanism with capacity control. This mechanism employs an evolutionary approach to achieve a dynamic system optimal allocation of network permits in a computationally efficient manner. We prove that the proposed mechanism has the following desirable properties: (i) truthful bidding is a dominant strategy for each user on each day and (ii) the permit allocation pattern under the mechanism converges to a dynamic system optimal allocation pattern.     

An origin–destination based road pricing model for static and multi-period traffic assignment problems

To mitigate traffic externalities, we propose an origin–destination (OD) based road pricing model for traffic assignment problems. For elastic demand, we derive explicit optimal tolls for the OD-based pricing scheme. We also extend the model to a multi-period static traffic assignment (MSTA) where we derive analytically the route and OD-dependent tolls based on equilibrium conditions. We present some examples to show that the OD-based tolling scheme could improve the system welfare significantly, compared to the no-toll scenario (user equilibrium – UE).     

Achieving genuinely dynamic road user charging: issues with a GNSS-based approach

A variety of approaches to road user charging (RUC) for reducing congestion and raising revenue to maintain and improve transport infrastructure is in place in many countries; examples of such RUC include: an Electronic Fee Collection System in Singapore, Cordon Pricing in Oslo City in Norway, Zoned Based Pricing in London and Distance-Based Pricing (also called Pay-As-You-Drive) in Germany and Switzerland. With the development of satellite technologies, the introduction of dynamic pricing becomes possible, affording an opportunity for RUC to fully reflect the ‘Polluter Pays Principle’. This paper provides critical and comparative assessments of existing road user charging (RUC) systems with reference to technological limitations and public and political acceptability. The paper then goes on to demonstrate a system architecture for a Global Navigation Satellite System (GNSS) based dynamic road user charging system capable of considering dynamic variables. Finally we consider the feasibility of the proposed system in relation to technology readiness and public acceptability. We then consider some potential wider benefits from the introduction of a comprehensive system that could be highlighted to justify the cost of development and implementation as well as to improve public and political acceptability. The paper ends with conclusions and future research directions.     

Air transport policy and its impacts on passenger traffic and tourist flows

This paper attempts to derive policy indices to quantify the restrictiveness of the aviation regimes in the Asia-Pacific region, and use the indices to establish the relationship between people movement and liberalisation in policy. Australia and Singapore have the most liberalised environment in this region. Evidence has been found that passenger traffic between city-pairs has been hampered by the restrictive air transport policies. Restrictions on the air transport sector also have a substantial negative impact on bilateral tourist flows. Further liberalisation in this sector could help build up a stronger tourism industry.     

Freeway traffic congestion in Riyadh, Saudi Arabia: attitudes and policy implications

The last few years have shown an unprecedented increase in traffic congestion in Riyadh, Saudi Arabia, especially on radial freeways. Unorganized distribution of land uses, inefficient traffic management, and low-cost automobile use have been major contributors to the problem. This article shows a strong awareness amongst drivers of the negative consequences of the congestion problem. Interviewees have strongly supported several land use, traffic management and transportation provision measures to alleviate freeway congestion but have strongly opposed increasing automobile travel costs. The study suggests an integrated approach to reduce the congestion problem through integrated policies for land use, economics and transportation.     

Relevance of airport accessibility and airport competition

Airport accessibility is an important criterion for airport competition. The relevance of airport accessibility and airport competition was studied in this paper based on the panel data collected from nine large airports in Jiangsu province, China from 2005 to 2014. The results showed that the cost of expense, time and fatigue for the arrival at the airport are proposed to quantify levels of fastness, economy and amenity for the passengers to arrive at airport. The airport accessibility is significantly affected by airport passenger traffic and airline frequency. The passenger traffic can be increased by 2% with 1% increase of airport accessibility based on the analysis results of the nine large airports in Jiangsu province.     

Accounting for population exposure to vehicle-generated pollutants and environmental equity in the toll design problem

The emissions generated by motor vehicles remain a major source of air pollutants that affect public health and contribute to anthropogenic climate change. These negative externalities can be reduced, in part, with the implementation of environmentally oriented road pricing schemes, which can be designed using optimization-based approaches. In this paper, a toll design problem is proposed for determining toll locations and levels that minimize the expected human exposure to air pollutants and the related environmental inequalities, subject to constraints on pollutant concentration levels and implementation costs. The practical use of the proposed problem is hindered in most real-world applications by the computational costs associated with the evaluation of candidate solutions, as is common for network design problems. Furthermore, the problem cannot be expressed analytically given the multiple types of models (e.g., traffic assignment, emissions, air dispersion models) that would be required to evaluate a single design alternative. For these reasons, a derivative-free surrogate-based solution algorithm is proposed for mixed integer problems like the ones considered here. Numerical examples are used to illustrate possible applications of the proposed model and to test the performance of the surrogate-based algorithm. Relative to a joint simulated annealing-genetic algorithm heuristic and a genetic algorithm-based approach, the proposed algorithm found better solutions in fewer function evaluations.     

Preventive maintenance of road pavement with microsurfacing—an economic and sustainable strategy

To ensure a good quality level of road pavements, it is essential to perform preventive maintenance before they are irreparably damaged. Treatments for preventive maintenance are a solution that is recognized but still in the acceptance phase; effective models covering different combinations of techniques and intervention times and assessing economic and environmental benefits are lacking. The present study aimed to respond to the abovementioned issues, using microsurfacing as the subject of analysis. Several structures and different interventions were evaluated, conducting an economic analysis over their life cycles and an environmental study evaluation using emission factors. The most advantageous solution included the maximum possible number of treatments of preventive maintenance with microsurfacing applied consecutively. This scenario ensures economic and environmental benefits. Additionally, it became clear that it is economically advantageous to design pavements for longer lifetimes.     

Travel,roads, risks and volunteers

International volunteers often travel to destinations (low- and middle-income countries) that carry a greater chance of being involved in a road-related injury and a possible fatality. Within this cultural exchange, tourists move from safe roads and cars to those that are potentially unsafe. Is this all part of the adventure of volunteering or should the tourist industry take some responsibility? This paper highlights the intersection between tourism and road injury and fatality risks (as pedestrians or in vehicles) with special attention to the longer term volunteer traveller. Social science theory underpins some of the discussions around risk and travel. A brief consideration of the international road traffic death and injury crisis and the emergence of the recognition that this impacts upon tourist safety is explored as backdrop to discussions. Tourism relies upon the ability for people to travel in and around the countries they travel to, often taking on the local travel arrangements prevalent in their destination. These local travel arrangements enable leisure tourists to explore their destination and volunteer travellers to live and work as locals. Is it time to consider and further the research on road risks as a growing feature of tourism?