1,721,016 research outputs found
Connectivity carbon and noise levels in the airport neighbourhood
No full textMany airport connectivity measures have been studied and proposed in the literature to capture both the effects of increased/reduced airport connectivity and the quality level of the connections. This study focuses on the relationship between connectivity – measured by air links and number of flights – and airport carbon/noise local levels. Although airport connectivity evokes the perception of geographical distances covered by air services, on ground connectivity consequences affect directly airport neighbourhood. Increased airport connectivity generally generates increasing number of airport movements that, in turn, produce higher levels of environmental externalities, such as noise and carbon emissions, mainly on local communities. To quantify such relationship, the Viable Connectivity Index (VCI)is proposed, which combines connectivity and noise/carbon levels at the airport. The index could be used as a preliminary test of airport operator policy actions to identify suitable policies addressed to reduce their noise and carbon amount and keep at the same time good connectivity levels. The test case of Bologna airport - a large regional airport in Northern Italy - is also discussed
An agent framework to support air passengers in departure terminals
No full textAirports are complex nodes performing several roles such as interchange terminal, shopping and relaxing center, meeting area for short-time business activities. Airport operators pay great attention to financial profits from their managed assets, while passengers desire spending their slack time inside the terminal in a pleasant way after wasting time in queues and controls to access the gate areas. In such a context, an agent framework is proposed to support travelers' slack time by providing purchase suggestions potentially interesting for them. Recommendations are computed by taking into account passengers' interests, their current position inside the departure terminal and the commercial opportunities available therein
Improving taxi-out operations at city airports to reduce CO2 emissions
No full textCity airports cause many environmental concerns on population living in their neighbourhood and several actions are often imposed to airport operators and other involved stakeholders in order to reduce impacts and improve the life quality of neighbouring inhabitants. While some solutions have been widely studied – e.g., green surface accessibility – some others, such as taxi-out procedures, have received less attention. However, taxi-out procedures, which are part of the Landing and Take-Off (LTO) cycle, generate a remarkable amount of the whole airport environmental impact, especially carbon emissions. The goal of this paper is to propose an element-by-element approach that could help stakeholders to adopt targeted solutions. Particularly, the airport activity contributing to the airport carbon impact is split into elementary segments in order to compute the environmental effects produced by each elementary source of pollution. The advantage of this approach is the identification of targeted actions on specific segments, which generates more positive effects for the several involved stakeholders. While the study focuses on taxi-out procedures, the proposed approach is general and can be applied widely to simulate other airport activities that contribute to the airport carbon impacts
Users’ acceptance of connected and automated shuttles for tourism purposes: A survey study
Full text linkIn recent years, autonomous vehicles have received increasing attention and many studies in the literature have discussed the potentialities and the opportunities they could offer. Despite the potential benefits, mainly related to the expected reduction in accidents and congestion phenomena as well as the potentially improved social inclusion of people with driving difficulties (e.g., people with physical disabilities or elderly people), many aspects remain to be addressed, mainly for understanding users’ acceptance in the case of collective transport vehicles. This study proposes an analysis based on a survey aimed at exploring user’s preferences with respect to the use of autonomous shuttles (ASs) for tourism purposes. The main correlations between the variables considered and the preferences of potential users have been discussed. Interviewees expressed high confidence in AS technology, although the analyses performed about willingness to pay show that users give more relevance to the provided transport services than the AS technology
Impacts of connected autonomous vehicle platoon breakdown on highway
No full textConnected Autonomous Vehicles (CAVs) are seen as an opportunity to improve traffic efficiency and safety. However, further studies are needed to prove such positive effects. Particularly, there is a lack of quantitative research on the impacts of CAV breakdown in mixed traffic flow conditions (i.e., CAVs and Human Driven Vehicles, HDVs). The aim of this research is to explore the impacts generated by the breakdown of the leading vehicle of a CAV platoon in mixed traffic conditions, which in turn generates CAV platoon breakdown (i.e., platoon dispersion), by considering several CAV market penetration rates (MPRs) and platoon size. In this perspective, a control algorithm (“avoidance algorithm”) for modelling CAVs and HDVs behaviour to avoid obstacles (i.e., breakdown CAV platoon) has been developed and tested on some simulation scenarios in order to derive key traffic flow parameters. The dynamic characteristics of traffic flow with CAV platoon breakdown have been explored for both low and high traffic flow volumes. Finally, potential conflicts, congestions, as well as energy consumption and CO2 emissions resulting from the breakdown of CAV platoons in mixed traffic streams have been assessed and discussed. Results suggest that (1) CAV platoon breakdown can reduce the traffic capacity by about 20 %; (2) higher CAV MPRs are more suitable for enhancing highway safety even in breakdown conditions, decreasing energy consumption, and reducing CO2 emissions; (3) platoon size should be limited to 4, since larger sizes affect traffic safety, increases vehicle average delay time as well as energy consumption. The obtained results provide useful insights for transportation planners and transport infrastructure management companies to design and apply policies aimed at improving driving conditions, traffic quality, and safety on highways
An element-by-element approach for a holistic estimation of the airport carbon footprint
No full textThe identification of carbon emission sources and their related impacts is of a great relevance to set suitable airport policies. Particularly, addressing the most significant emission sources allows finding more efficient solutions and identifying more effective policies, as some studies already suggested (e.g., Morrinson 2009; Liebert and Niemeier 2010; Postorino and Mantecchini 2014; Postorino et al. 2016). In line with the previous considerations, this chapter proposes a methodological framework to identify effective policy actions based on the segmentation of carbon emission sources at the airport. In other words, the relevant airport activity (such as airside, terminal and landside operations) contributing to the airport carbon impact is split into elementary segments. The environmental effects produced by each elementary source of pollution are computed, and then actions that could be implemented to reduce or possibly remove the produced environmental impacts are identified
Green airport investments to mitigate externalities: Procedural and technological strategies
No full textTransport systems are important pollution sources, mainly in terms of greenhouse gases, noise and land consumption. To mitigate the problem and safeguard airport development at the same time, the involved stakeholders are fixing goals, priorities and duties in order to promote the sustainable development of the air transport industry at global level and the wellness of local communities as well. It is desirable to estimate airport noise and carbon impacts in order to suitably manage them and identify strategies in line with the concept of green economy. In this chapter, a general framework to identify optimal procedures and methods to evaluate the effectiveness of policies addressed to reduce airport impacts on the airport surroundings is proposed. The case study of the airport of Bologna is presented as an example of Transport Company that effectively operates to minimize its noise and carbon impacts. According to the proposed general framework, impacts and estimated costs to achieve the status of green company have been computed
Analisi del legame fra traffico autostradale e indicatori economici nazionali - Analysis of the link between Italian motorway traffic and national economic indicators"
No full textThis work intends to analyse the relationship between the increase in Italian motorway traffic (light and heavy vehicles) and national economic aggregated indices such as GDP (Gross Domestic Product) and IPI (Industrial Production Index). The ratio between the rate of increase of the motorway traffic of light vehicles and the rate of growth of GDP remain higher than one during the whole period considered, although in the long period this ratio shows a statistically significant decreasing trend. On the other hand, during the period considered, the rate of increase of the motorway traffic of heavy vehicles is higher than the rate of growth of IPI, but so far the ratio between these latter rates has not shown any decreasing trend. Italian motorway transport, especially as far as heavy vehicles are concerned , is not yet a “mature” market. This work also gives some estimates of the elasticity of light vehicle motorway demand respect to changes in GDP and of the elasticity of heavy vehicle motorway demand respect to changes in IPI. The analysis, eventually, gives an estimate of the elasticity of Italian motorway demand respect to changes in the average fare per vehicle-kilometre”. Nevertheless, this latter variable is statistically significant only in case of heavy vehicles - SOMMARIO. In questa nota è stato analizzato il legame fra traffico autostradale, in veicoli leggeri, e PIL nazionale, e fra traffico autostradale, in veicoli pesanti, e indice di produzione industriale nazionale (IPI).I dati rilevati, relativi ad un periodo di circa 20 anni (1982-2000), mettono in evidenza come i tassi di incremento del traffico leggero in autostrada siano stati praticamente sempre superiori ai tassi di variazione del PIL. Analogamente i tassi di incremento del traffico pesante sono risultati sempre superiori ai tassi di variazione dell' IPI. Mentre però il rapporto fra tasso di incremento del traffico leggero e tasso di incremento del PIL mostra una tendenza alla diminuzione, almeno sul lungo periodo, il rapporto fra tasso di incremento del traffico pesante e tasso di incremento della produzione industriale mostra invece un andamento costante, decisamente superiore ad uno, senza tendenza alla diminuzione: malgrado i problemi di congestione del sistema autostradale italiano, il traffico pesante cresce a tassi continuamente superiori a quelli della produzione industriale.
Nel corso della nota sono state condotte alcune stime dell'elasticità della domanda di trasporto, in veicoli leggeri e in veicoli pesanti, rispettivamente rispetto al PIL e all’IPI. Inoltre è stata ricercata una stima della elasticità della "tariffa media per veicolo-chilometro": quest'ultima variabile è comunque risultata statisticamente significativa solo nel caso dei veicoli pesanti. Tenendo conto di tutte le limitazioni e approssimazioni dei modelli adottati, che fra l'altro forniscono valori per la stima della elasticità non sempre molto vicini fra loro, si può ritenere che l’elasticità della domanda di trasporto autostradale, in veicoli leggeri e in veicoli pesanti, rispettivamente rispetto al PIL e all’IPI, sia nettamente superiore ad uno.
Il mercato del trasporto autostradale non sembra avere raggiunto la “maturità”. Il mercato autostradale sembra tendere alla maturità nella componente passeggeri, per quanto, deve essere sottolineato, anche negli ultimi anni del periodo preso in considerazione, il rapporto fra tassi di incremento del traffico in veicoli leggeri e tassi di incremento del PIL continua a mantenersi superiore ad uno
A cluster analysis of university commuters: Attitudes, personal norms and constraints, and travel satisfaction
Full text linkHigher education institutions are recognised as settings where the community’s awareness of sustainable mobility can be strengthened or reshaped. The first objective of the present study was to identify groups of commuters based on their modal choice in a large higher education institution in Italy. The second objective was to compare the groups on socio-demographic and psychosocial variables, specifically attitudes, personal norms, personal constraints, and travel satisfaction. The cluster analysis revealed five different types of commuters: car-oriented, two-wheeled urban users, pedestrians, long-distance commuters, and regular bus users. Attitudes, personal constraints and norms, and satisfaction differed in the five groups of commuters. The present study provides insights for behavioural change programmes and organizational policies on sustainable mobility
Flusso orario di punta e traffico giornaliero medio sulla rete autostradale italiana - Peak hour flow and average annual daily traffic on Italian motorways
No full textIn this paper the problem of determining the Design Hour Volume (DHV) from the Annual Average Daily Traffic (AADT), for Italian motorways, has been faced. At the planning stage the AADT is the traffic data to start from: in order to determine the expected level of service (LOS) it is, however, necessary to estimate the DHV. Statistic analysis of the sample of data has evidenced that the relationship DHV/AADT is maintained almost constant versus an increase in the AADT and that the data of two lane motorways and of three lane motorways can be considered belonging to the same population. The determination of the level of service (LOS) is what is of interest mainly for practical purposes: the way in which the LOS varies versus the DHV/AADT relationship has been therefore studied. In order to examine the sensitivity of LOS more effectively, LOS has been identified, not only, as usual, through a representative letter, but also through another variable: the “percentage of inner density”. The comparison between the predicted and actual LOS, for a “hold-out sample” has evidenced that there is a substantial agreement. The interval estimated for relationship DHV/AADT in present research is online with the most recent American studies.- SOMMARIO. In questa nota è stato affrontato il problema della determinazione del rapporto FOP/TGM: fra il flusso orario di picco (FOP) e il traffico giornaliero medio (TGM) per le autostrade italiane, per fini di pianificazione e progettazione . In sede di pianificazione, generalmente, il TGM è il dato di traffico di partenza: per determinare le condizioni di circolazione della infrastruttura, ossia il livello di servizio (LDS), è però necessario valutare il FOP. L’analisi statistica del campione dei dati ha evidenziato: che il rapporto FOP/TGM si mantiene pressoché costante all’aumentare del TGM; che i dati delle autostrade a 2 corsie e a 3 corsie possono essere considerati appartenenti ad un’unica popolazione. E' stato determinato un intervallo di confidenza per il valore atteso del rapporto FOP/TGM: in modo da ottenere un intervallo di valori utilizzabili in fase di progettazione e pianificazione. La determinazione del LDS è ciò che interessa maggiormente ai fini pratici progettuali: è stato pertanto studiato come varia il LDS al variare del rapporto FOP/TGM. Per esaminare più efficacemente la sensibilità del LDS esso è stato individuato, oltre che dalla usuale lettera rappresentativa, da un'altra variabile, definita nella presente nota: “percentuale di densità interna”. Dai risultati ottenuti, considerando la differenza fra i livelli di servizio in maniera continua, avvalendosi della “percentuale di densità interna”, si evince che normalmente i livelli di servizio calcolati agli estremi dell’intervallo di confidenza differiscono di un solo livello di servizio; in alcuni casi differiscono fra 1 e 2 livelli; in un solo caso è stata osservata una differenza di due livelli di servizio. Allo scopo di rilevare la validità pratica dei risultati ottenuti è stata condotta una analisi dei LDS su un campione di dati di riserva. Il confronto fra i LDS previsti e rilevati, per il “campione di dati di riserva”, ha evidenziato che sussiste una sostanziale concordanza. E' stato infine eseguito un raffronto fra i valori del rapporto FOP/TGM ottenuti nel caso italiano con quelli proposti in letteratura, in particolare negli Stati Uniti. E’ emerso che i risultati ottenuti nella presente ricerca sono in linea con gli studi americani più recenti: questi studi recenti, raffrontati con quelli più datati, mettono in evidenza che negli Stati Uniti sembra esserci una tendenza alla diminuzione del rapporto FOP/TGM nel tempo
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