Optimal Scheduling of Evacuation Operations with Contraflow

Congestion due to evacuations can be catastrophic and life threatening. The sudden increase in demand will result in excessive loads on roads not typically designed to handle them, leading to network breakdown at the worst possible time. Moreover, since building new roads is infeasible, efficient utilization of the available network resources during disasters becomes one of the few options available to facilitate the movement of residents to safety. One option is to address the demand side of the problem, through demand scheduling. By scheduling the evacuation demand over a longer period, the congestion is staved off and network degradation is delayed. Advising traffic on when to evacuate, where to evacuate, and which route to take has the potential to improve evacuation times, especially in no-notice emergency conditions. Another option is to address the supply side of the problem, through network re-design. By reversing the direction of wisely selected lanes in a process known as contraflow, a temporary increase in the operational capacity is achieved without any major infrastructure changes. Both options, if planned correctly, have the potential to greatly ease network degradation and allow evacuees to reach safety sooner. Therefore, the ability to determine the joint optimal demand scheduling and network contraflow policies is of critical nature to the success of any evacuation plan. The objective of this study is to develop a simulation-based dynamic traffic assignment model that minimizes network clearance time at a minimum cost to the travelers by jointly considering demand scheduling and contraflow strategies

Comparative study of proactive and reactive routing protocols in vehicular ad-hoc network

In recent years, the vehicular ad-hoc network (VANET), which is an ad-hoc network used by connected autonomous vehicles (CAV) for information processing, has attracted the interest of researchers in order to meet the needs created by the accelerating development of autonomous vehicle technology. The enormous amount of information and the high speed of the vehicles require us to have a very reliable communication protocol. The objective of this paper is to determine a topology-based routing protocol that improves network performance and guarantees information traffic over VANET. This comparative study was carried out using the simulation of urban mobility (SUMO) and network simulator (NS-3). Through the results obtained, we will show that the choice of the type of protocol to use depends on the size of the network and also on the metrics to be optimized

Parking facilities in urban areas: air and noise impacts

Parking problems in major urban centers are typically an accumulation of the effects of several factors, including short-sighted urban planning regulations, pricing distortions, ineffective enforcement, and vague transport and parking policies. This paper evaluates the environmental impacts at a typical proposed parking facility in the greater Beirut area, where parking deficiencies have increased significantly in recent years due to development and reconstruction efforts. The assessment focuses on vehicle-induced pollutant and noise emission impacts, which are evaluated along with possible mitigation measures to reduce or eliminate potential adverse impacts. The assessment showed that the greatest potential impacts would occur during the construction phase. Increased parking capacity proved to have a more adverse effect on air quality than on noise levels. Although air quality and noise levels were not significantly affected with respect to projected baseline levels and under normal operating conditions, mitigation measures are still needed because of the urban nature of the are

Economics of mitigating greenhouse gas emissions from solid waste in Lebanon

Global climate change has been one of the challenging environmental concerns facing policy makers over the past decade. The characterization of the wide range of greenhouse gas (GHG) emission sources and sinks, as well as their behavior in the atmosphere, remains a continuing activity in many countries. Solid waste is considered a source of greenhouse gas emissions owing to microbial decomposition of organic materials, which constitute the greater portion of solid waste. The extent of these emissions is highly dependent on waste management practices. In many countries, landfills remain an essential part of any waste management system and often the only economic form of municipal solid waste disposal. This paper describes solid waste management practices in Lebanon, estimates the corresponding current and future greenhouse gas emissions from this sector, and proposes mitigation alternatives to reduce these emissions. An economic assessment of these alternatives in the context of characteristics specific to the country is also presented in terms of equivalent cost of emission reduction. <br/

Economics of mitigating GHG emissions from MSW management in developing countries

Global climate change has been one of the challenging environmental concerns facing policy makers over the past decade. The characterization of the wide range of greenhouse gas (GHG) emission sources and sinks, as well as their behavior in the atmosphere, remains a continuing activity in many countries. Solid waste is considered a source of greenhouse gas emissions owing to microbial decomposition of organic materials, which constitute the greater portion of solid waste. The extent of these emissions is highly dependent on waste management practices. In many countries, landfills remain an essential part of any waste management system and often the only economic form of municipal solid waste disposal. This paper describes solid waste management practices in Lebanon, estimates the corresponding current and future greenhouse gas emissions from this sector, and proposes mitigation alternatives to reduce these emissions. An economic assessment of these alternatives in the context of characteristics specific to the country is also presented in terms of equivalent cost of emission reduction. <br/

Effect of network roadway aggregation levels on modeling traffic-induced emissions inventories

Traffic-induced emissions pose a serious threat to air quality in heavily congested urban centers. While air quality can be characterized through field measurements and continuous monitoring, forecasting future conditions depends largely on estimating vehicle-emission factors coupled with mathematical modeling. Traffic and environmental planners have relied on overall average network speed in conjunction with speed-based emission factor models to estimate traffic emissions. This paper investigates the effect of three levels of roadway network aggregation, macro-scale (overall network basis), meso-scale (roadway functional class basis) and micro-scale (link-by-link basis) on emission inventories. A traffic model and an emission factor model were integrated to determine total emissions in the future Beirut Central District area for these three modeling approache

New Advances and Future Possibilities in Forming Technology of Hybrid Metal–Polymer Composites Used in Aerospace Applications

Fibre metal laminates, hybrid composite materials built up from interlaced layers of thin metals and fibre reinforced adhesives, are future-proof materials used in the production of passenger aircraft, yachts, sailplanes, racing cars, and sports equipment. The most commercially available fibre–metal laminates are carbon reinforced aluminium laminates, aramid reinforced aluminium laminates, and glass reinforced aluminium laminates. This review emphasises the developing technologies for forming hybrid metal–polymer composites (HMPC). New advances and future possibilities in the forming technology for this group of materials is discussed. A brief classification of the currently available types of FMLs and details of their methods of fabrication are also presented. Particular emphasis was placed on the methods of shaping FMLs using plastic working techniques, i.e., incremental sheet forming, shot peening forming, press brake bending, electro-magnetic forming, hydroforming, and stamping. Current progress and the future directions of research on HMPCs are summarised and presented.publishedVersio