Smart vs conventional motorways: environmental impact assessment under realistic traffic conditions

Abstract This research aims at assessing the environmental impacts exerted by a smart motorway compared to those of a traditional motorway. The study has global policy implications: it takes into account the impacts due to the construction and maintenance of the infrastructure and the environmental effects produced by the traffic emissions, taking into account smart technologies and truck platooning regulation. Through a classical LCA approach, 1 km-long smart motorway with 2 m-high embankment was assumed as the functional unit for the analysis. A realistic traffic condition has been considered. A comparison between environmental effects produced by the use of virgin material and by Reclaim…

Exploring Effects of Area-Wide Traffic Calming Measures on Urban Road Sustainable Safety

Traffic calming schemes refer to a combination of road network planning and engineering measures to minimize undesirable effects of traffic in residential areas. The traffic calming role in urban road network management is, indeed, to enhance road safety as well as other aspects of liveability for the citizens; in this context accident reduction can be a realistic objective. Several studies highlight that traffic calming treatments can significantly reduce road accidents in urban areas. Nevertheless, the increase of the accident rate per kilometre travelled has been found in urban areas as result of the so-called accident migration phenomenon. Starting from these considerations, the paper d…

Soluzioni innovative per le intersezioni stradali: un caso di turborotatorie

Le intersezioni tra gli assi stradali costituiscono punti particolarmente critici per le condizioni operative della rete viaria, sia sotto il profilo della capacità e dei livelli di servizio, sia sotto quello della sicurezza . Nell’ambito degli interventi “strutturali” di moderazione del traffico stradale e di messa in sicurezza dei nodi ad alto rischio d’incidentalità, sempre più frequentemente si ricorre alla realizzazione di rotatorie. L’impiego estensivo di tale tipologia di intersezione, che si è registrato soprattutto nel corso dell’ultimo decennio, deriva, in primo luogo, da numerosi vantaggi che contraddistinguono le rotatorie rispetto ad equivalenti schemi tradizionali (intersezion…

Conversion of existing roundabouts into turbo-roundabouts: case studies from real world, Journal of Civil Engineering and Architecture 6(8)

Compared with roundabouts the main advantages of turbo-roundabouts are the reduction in the number of potential conflicting points and the lower speed of vehicles through the intersection; they both can improve road safety conditions at the junction. Moreover, the physical delimitation among lanes limits the side-by-side accident risk. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. The present paper has three main objectives : 1) to discuss general design criteria and functional principles of turbo roundabouts; 2) to give the geometric d…

EVALUATING CAPACITY AND EFFICIENCY OF TURBO-ROUNDABOUTS.

Recent evolution of roundabout design has been directed towards the so-called turbo-roundabout, with the aim of ensuring better safety conditions than those afforded by traditional schemes. The few turbo-roundabout installations so far implemented have not allowed sufficient research in order to analyze operational conditions and capacity models validated by field observations. In any case the theoretical approach to the functional study of turbo-roundabouts undoubtedly involves more complex aspects compared to typical roundabouts because of the paths of entering streams (constrained to get onto physically separated lanes), the “turbine” configuration of the circulatory carriageway, as well…

Digital image analysis technique for measuring railway track defects and ballast gradation

Abstract In order to guarantee safety and driving comfort and to maintain an efficient railway infrastructure, the first step is to carefully monitor the track geometry and wear level of the materials constituting the superstructure. To that end diagnostic trains are widely used on main lines, in that they can detect several geometric track parameters and rail wear, but under no circumstances they can yet detect ballast gradation. Due to the practical implications for the planning of maintenance operations on the railway network, this article presents a “DIP” digital image processing technique for measuring the transverse profile and corrugations of the rails as well as ballast gradation. T…

Conversion of Existing Roundabouts into Turbo-Roundabouts: Case Studies from Real World

Compared with roundabouts the main advantages of turbo-roundabouts are the reduction in the number of potential conflicting points and the lower speed of vehicles passing through the intersection, they both can improve safety conditions at the junction. Moreover, the physical delimitation among lanes limits the side-by-side accident risk. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. The present paper has three main objectives: (1) to discuss general design criteria and functional principles of turbo roundabouts, (2) to give the geometr…

La pianificazione stradale in Sicilia, prima dell’unità d’Italia

Comparative Analysis of Four New Alternative Types of Roundabouts: “Turbo”, “Flower”, “Target” and “Four-Flyover” Roundabou

Analysis of literature shows that “modern roundabouts” nowadays exist in all European countries, as well as in more than 60 countries elsewhere in the world. Nowadays, a growing number of studies, presented in scientific and professional literature, point out a poor traffic safety characteristics of “standard” two-lane roundabouts and lower capacity then was expected. These problems are resolved in more ways in different countries; however the solution, whereby the number of conflict spots is diminished has proven to be the most successful. Lower number of conflict spots is one of characteristics of the alternative types of roundabouts. The alternative types of roundabouts are usually more …

A grid of material and immaterial laboratories for supporting the sustainability of transportation: the RESET project in Sicily

Transportation is a crucial sector, to be suitably approached in order of getting human activities in more environmentally sustainable paths. In fact, in developing, as well in less developing, countries people and freights mobility are responsible of important amount of pollutant emissions and are cause of significant levels of energy consumptions. In this paper, a Sicilian regional project is presented, aiming at establishing an interconnected grid of material and immaterial laboratories. These laboratories, that are devoted at inducing more virtuous behaviors in the transportation policies, are constituted by equipment and software tools, mainly located in the region’s universities, acti…

Electromechanical characterization of a bimorph piezo for Energy Harvesting applications in road infrastructures

Piezoelectric materials can be used as a means of transforming ambient vibrations into electrical energy that can be stored and used to power other devices. With the recent surge of micro scale devices, piezoelectric power generation can provide a convenient alternative to traditional power sources used to operate certain types of sensors/actuators, telemetry, and MEMS devices. However, the energy produced by these materials is, in many cases, far too small to directly power an electrical device. In the present study, piezoelectric devices will be investigated and experimentally tested to determine each of their abilities to transform ambient vibration into electrical energy. Tested piezoel…

Embedding “roadside equipment” into environmental assessment of transportation system: the case of safety barriers

The work arises from the consideration that the environmental impact of a road cannot be limited to the analysis of its constituent materials, even if correctly analyzed in their life cycle. In fact, a given road not only consists of the pavement and subgrade, but also includes several different components and accessories (e.g. road marking, drainages, safety barriers, etc.) that contribute to set a road infrastructure in operative conditions. As a matter of fact, only limited attention has been paid in the scientific literature to roadside components, unlike pavement and traffic flow. In the present work, the environmental burden of one of these components, i.e. the safety barrier, has bee…

IMAGE ANALYSIS FOR DETECTING THE TRANSVERSE PROFILE OF WORN-OUT RAILS

Abstract — Over its useful life a railway track is subject to many mechanical and environmental stresses which gradually lead to its deterioration. Monitoring the wear condition of the railway superstructure is one of the key points to guarantee an adequate safety level of the railway transport system; in this field, the use of high-efficiency laser techniques has become consolidated and implemented in diagnostic trains (e.g. the “Archimede train” and the “Talete train” ) which allow to detect the track geometric parameters (gauge, alignment, longitudinal level, cross level, superelevation defect, etc.) and the state of rail wear (vertical, horizontal, 45-degree etc.) with very high accurac…

Turbo-Roundabout: Case Study of Driver Behavior and Kinematic Parameters of Light and Heavy Vehicles

AbstractThis research compared kinematic and behavior parameters of light and heavy vehicles at turbo-roundabouts. This is of interest because heavy vehicles can influence turbo-roundabout function...

Performance Analysis of Basic Turbo-Roundabouts in Urban Context

AbstractA turbo roundabout is a new type of canalized multilane intersection in which the physical separation between lanes helps to prevent side collisions when crossing the roundabout. This paper presents an estimation of capacity, delays and level of service of basic turbo roundabouts in undersaturation conditions, considering both vehicle flow and pedestrian traffic. The traffic performance model was developed by evaluating the capacity for each entry lane. Owing to the geometric features of the intersection, the total entry capacity is obtained by considering different values of the pedestrian impedance factor and degree of saturation at both the right-turn and left-turn lanes.

Road restraint systems monitoring with stereoscopic dip-technique

Road restraint systems (RRS) are used to protect vehicle occupants from dangerous roadside elements such as rigid obstacles, slopes, utility poles, etc. The crashes on a road restraint system damage its structure and, therefore, the functional behavioral; for this reason is required monitoring the RRS into their operational conditions. The research addresses the problem of the measurement of safety barrier (SB) deformations by means digital image processing technique (DIP). This technique is founded on the analysis of high resolution photos/videos, obtained by means of 3D camera installed into a data vehicle. The DIP technique has been used for evaluating the longitudinal safety barriers de…

University campuses as small-scale models of cities: Quantitative assessment of a low carbon transition path

Abstract The energy efficiency interventions and rehabilitation actions regarding university campuses are characterized by an emblematic impact, representing significant examples of good practices that a given community could adopt, even at the city level. Starting from the idea that campuses may be regarded as small scale models of cities, a quantitative method for estimating to which extent the adoption of a given set of interventions by a municipality could contribute to make such city close to a nearly zero energy profile is proposed. To accomplish this task, the study considers the low carbon transition path of the campus of the University of Palermo and applies a simple method that, i…

Tramway Track: A New Approach for Measuring the Transverse Profile of Worn-Out Rails

Abstract Monitoring the wear condition of the tramway superstructure is one of the key points to guarantee an adequate safety level of the light rail transport system. The purpose of this paper is to suggest a new non-conventionalprocedure for measuring the transverse profile of rails in operation by means of image-processing technique. This methodological approach is based on the “information” contained in high-resolution photographic images of tracks and on specific algorithms which allow to obtain the exact geometric profile of the rails and therefore to measure the state of the rail-head extrados wear.

Analysis of Kinematic Parameters and Driver Behavior at Turbo Roundabouts

This study focuses on both vehicle kinematic parameters (speed and acceleration) and behavior parameters (critical interval and follow-up time) of drivers at turbo-roundabouts. Empirical evaluations of such parameters can be helpful in calibrating traffic microsimulation models or assigning behavior parameters to closed-form capacity models in turbo-roundabouts (gap-acceptance capacity models) and are also related to evaluation of vehicles pollutant emissions. The research was based on traffic process observed in the first turbo-roundabout implemented in the city of Maribor in Slovenia. In 2016 a great number of traffic samples were taken with high-frame-rate video recordings [>50 frames pe…

Estimation of Measures of Effectiveness (MOE) for the C-Roundabouts

The C-roundabout (cyclist roundabout) is a new multi-lane roundabout designed to improve the safety of cyclists at and make multi-lane roundabouts more cyclist-friendly. The geometric layout of C-Roundabouts allows the decrease of the vehicle speeds through the roundabout to around 30 km/h. The rare C-roundabout installations so far implemented in the world have not allowed analysing the capacity by means empirical data. In the light of this considerations, the main objective of the paper is to give a theoretical closed-form model for evaluation the measures of effectiveness MOE (capacity, delay, queues) of the C-Roundabouts.

Flower roundabouts: estimation of capacity and level of service

The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety. Among the most interesting solutions there are such schemes as spiral, turbo and flower roundabouts, which are similar to traditional roundabouts. Although these solutions provide a traffic travels counterclockwise around a central island and in which entering traffic must yield to circulating traffic, the newly designed schemes generally offer modes of traffic flow regulations which highly differ from those used in conventional roundabouts. Of considerable i…

Sustainable Mobility in Park Areas: The Potential Offered by Guided Transport Systems

The project choices to design and manage a transport infrastructure system are extremely hard in thinly populated areas like, for instance, protected areas and mostly parks. In actual fact, the need for promotion and development of these areas, often characterized by large surfaces, contrasts with the necessity to preserve their inestimable natural value. The transportation demand in extremely sensible environmental contexts can be satisfied by providing incentives to use reduced-impact means of transport, regulating adequately the vehicle traffic flow and promoting the intermodality between private and public transport systems. Apart from performing their own traditional functions, these s…

Benefits of area-wide traffic calming measures: outcomes still to assess

The role of traffic calming schemes in urban network management is mainly to minimize undesirable effect of traffic in residential areas; in this context accident reduction can be a realistic objective. Several studies, indeed, inform us that traffic calming is a major part of the treatments available to reduce road accidents in urban areas. Paradoxically the increase of the accident rate per kilometre travelled has been observed in the urban context as result of the wellknown accident migration phenomenon. In connection to these considerations, the effectiveness of traffic calming measures on road safety is discussed in this paper. Then, after a synthetic exposition of the conceptual formu…

Evaluation of the Safety Performance of Turbo Roundabouts by Means of a Potential Accident Rate Mode

Turbo roundabouts are a particular road intersection layout, designed to increase the safety of double-lane roundabouts, while maintaining their excellent capacity. The main feature of this new concept of roundabout is the impossibility to move from one lane to another, provided by physical barriers marking the lanes. The paper shows an application to turbo roundabouts of a potential accident rate model, aiming to evaluate their safety improvement. Themodel is based on the concept of potential conflict: each vehicle involved in a general intersection performs a series of maneuvers which potentially imply a crash, according to the actual traffic. The number of accidents related to each criti…

Reducing Air Pollutants through Road Innovative Intersections

Road pollutant emissions are correlated mainly to infrastructural capacity and to traffic intensity and typology. With the aim to improve road intersections performances in the last years was designed many new geometric layouts, like turbo roundabouts and flower roundabouts. The main objective of this paper is carried out a comparative analysis between conventional and innovative roundabouts in terms of CO, CO2, NO and PM2,5 vehicular emissions, evaluated by means of COPERT Software which is developed as a European tool for the calculation of emissions from the road transport sector.

Applicazioni dell’image processing nel campo delle infrastrutture viarie. il caso della viabilità in esercizio

Nel settore delle infrastrutture di trasporto, si stanno sempre più sviluppando specifiche tecniche di rilievo automatico, ad alto rendimento, utilizzate per il monitoraggio dei parametrici caratteristici del traffico e di quelli geometrici dell’infrastruttura. Di particolare interesse per la loro semplicità, flessibilità d’uso, economia ed affidabilità sono le tecniche basate sull’image processing, che prevedono l’impiego sinergico di un sistema di monitoraggio e di elaborazione delle sequenze video registrate con strumentazioni digitali o analogiche. In questo ambito, le molteplici esperienze di ricerca già maturate hanno dimostrato la versatilità di tali procedure in numerose applicazion…

Contribution to the platoon distribution analysis in steady-state traffic conditions

The traffic flow analysis and the relevant vehicle distribution (“free-moving” or “platooned” vehicles) on highway facilities at uninterrupted flow has always had fundamental importance in Highway Engineering, with special reference to topics like traffic operations, car accidents, road safety and air pollution emissions. In light of this, the study suggests a calculation algorithm as a random test generator to simulate a steady state traffic flow and to provide time headways. Thanks to the outcome produced by numerical simulations, we analysed platoon distributions within traffic flows in a steady-state regime and showed the results of numerical analyses carried out by traffic random proce…

Evaluating the safety of platooned heavy vehicles: A case study

In the right lane of motorways with trucks' overtaking prohibition is very common the formation of platoons of heavy vehicles. Although this traffic controls strategies can increase the capacity of passing lane, in the right lane may occur increases of rear-end collisions. The purpose of this research was to evaluate the safety of the platooned heavy vehicles by means a closed-form stream model. The case study of the Italian motorway A22 was examined. The sampling of platoons was performed in four observation sections.In the research have been investigated platoons with 2/20 heavy vehicles for each platoon. Many traffic parameters have been evaluated: frequencies of the number of platoons, …

Turbo roundabouts:geometric design parameters and performance analysis

A turbo roundabout is a particular type of roundabout where entering and circulating lanes are bounded by traffic signs and by non-mountable curbs. The physical separation between lanes, both at entries and on the ring, helps to prevent side collisions crossing the roundabout. The main advantages of turbo roundabouts are: i) reduction in the number of potential conflict points; ii) lower speed of vehicles passing through the intersection; iii) safety conditions at the intersection due to lower risk of side-by-side accidents. Also, in some cases the capacities of turbo roundabouts are higher than the capacities of conventional roundabouts. This paper presents an estimation of capacity, delay…

Dalla relazione Possenti ai primi provvedimenti postunitari per il completamento e l’adeguamento della rete stradale siciliana

“TRAVERSA FERROVIARIA HP-BB” (HIGH PERFORMANCE BI-BLOCK SLEEPER)”

Comparative life-cycle assessment of conventional (double lane) and non-conventional (turbo and flower) roundabout intersections

Abstract This research studied and compared different construction techniques for the road subgrade, embankment and pavement of different types of roundabout intersections in order to assess their environmental sustainability. A Life Cycle Assessment (LCA) was carried out on double lane, turbo- and flower roundabouts. We considered virgin materials and reclaimed asphalt pavement (RAP) for the pavement construction. Also the environmental effects due to in situ lime stabilization of fine-grained soils were assessed in order to reduce the use of virgin material in road subgrades. The use of reclaimed asphalt pavement (RAP) can lead to a significant reduction in pollutant emissions and energy …

Determinazione dell’usura di rotaie tranviarie mediante analisi delle immagini con tecniche mono e stereoscopiche

La misura dei valori assunti dai parametri geometrici del binario e lo stato di usura delle rotaie, ormai da diversi anni viene effettuata con tecniche laser ad alto rendimento e con treni diagnostici (come ad esempio i treni Archimede e Talete per le ferrovie ordinarie). Nel presente lavoro viene descritta una nuova procedura per la stima dell’usura del profilo trasversale di rotaie tranviarie in esercizio mediante la tecnica dell’image processing; tale approccio metodologico si basa sulle “informazioni” contenute in immagini fotografiche ad alta risoluzione delle rotaie e su specifici algoritmi che permettono di ottenere l’esatto profilo geometrico delle rotaie stesse e quindi di poter mi…

Capacity and safety analysis of hard-shoulder running (HSR). A motorway case study

Abstract Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, relia…

Il monitoraggio degli interventi di messa in sicurezza cofinanziati dal PNSS. Esame di un caso studio

A Novel Technique for Monitoring the W-Beam Guardrails

The paper addresses the problem of the measurement of guardrails’ deformations by means automatic analysis of optical images. The technique is founded on the analysis of high-resolution photos, obtained by means of 3D camera installed into a data vehicle. The novel methodology has been used to calculate the longitudinal safety barrier deformations for one W-beam guardrails installed along a rural road in Italy. The procedure has shown that digital image analysis can be used with the aim to monitoring guardrails and, therefore, for guarantee reasonable levels of protection against serious ran-off-road crashes.

Right-turn Bypass Lanes at Roundabouts: Geometric Schemes and Functional Analysis

Right-turn bypass lanes can be implemented in conventional and innovative roundabout intersections to increase the capacity and improve the global functional performances. The Right-turn bypass lanes (also called slip lanes) can be distinguished according to the planimetric layout and the entry control type (stop, yield slip or Free Flow acceleration lane). This paper presents a closed-form model for the estimation of capacity, delays and level of service of roundabout equipped with Right-turn bypass lanes, considering the effect of geometric slip lane schemes, control type, vehicular and pedestrian flow. In order to examine the traffic conditions which can benefit from slip lane roundabout…

Prestazioni delle traverse ferroviarie: confronto tra dispositivi tradizionali ed innovativi

Automated Railway Signs Detection. Preliminary Results

Abstract Nowadays safety in railways is mostly achieved by automated system technologies such as ERTMS/ETCS. Nevertheless, on local railways (suburban and regional lines) several tasks still depend on the choices and actions of a human crew. With the aim to improve safety in such type of railways, this research proposes a system for the automatic detection and recognition of railway signs by means of the digital image processing technique. First field applications, carried out on the Italian railway network, show that the proposed system is very accurate (the percentage of correctly detected railway signs is about 97%), even at high train speeds.

Modello di capacità e valutazione delle prestazioni per le rotatorie a turbina.

L’evoluzione più recente delle intersezioni a rotatoria si è indirizzata verso schemi cosiddetti a turbina (turborotatorie) con l’obiettivo di garantire condizioni di sicurezza più elevate rispetto agli schemi tradizionali. I pochi esempi di realizzazione delle rotatorie a turbina non hanno tuttavia finora consentito di sviluppare metodi di analisi delle condizioni operative e modelli di capacità che possano vantare una validazione attraverso osservazioni di campo. In ogni caso, l’approccio teorico allo studio funzionale delle turborotatorie presenta aspetti decisamente più complessi di quelli delle rotatorie convenzionali sia a causa delle traiettorie dei flussi in ingresso (costretti ad i…

Environmental analysis of different construction techniques and maintenance activities for a typical local road

Abstract In this paper, considering the sever impact of road infrastructures on both the surrounding environment as well as on the consumption of locally available natural resources, different road construction techniques have been studied and compared, in order to be able to rank the best solution in terms of environmental sustainability. For the aims of this study, a Life Cycle Analysis has been carried out on a road infrastructure with the most representative geometrical characteristics among those widely used in Italy, in suburban areas, with the help of an appropriate software, the PaLATE. The environmental effects due to both the use of recycled materials, such as the Reclaimed Asphal…

A New High-Efficiency Procedure for Aggregate Gradation Determination of the Railway Ballast by Means Image Recognition Method

Abstract The mechanical characteristics of the railway superstructure are related to the properties of the ballast, and especially to the particle size distribution of its grains. Under the constant stress-strain of carriages, the ballast can deteriorate over time, and consequently it should properly be monitored for safety reasons. The equipment which currently monitors the railway superstructure (like the Italian diagnostic train Archimede) do not make any “quantitative” evaluation of the ballast. The aim of this paper is therefore to propose a new methodology for extracting railway ballast particle size distribution by means of the image processing technique. The procedure has been teste…

TURBO-ROUNDABOUT GENERAL DESIGN CRITERIA AND FUNCTIONAL PRINCIPLES: CASE STUDIES FROM REAL WORLD

Compared with usual roundabouts the main advantages of turbo-roundabouts are the reduction in the number of potential conflicting points and the lower speed of passing vehicles through the intersection; they both can improve road safety conditions at the junction. Also, the physical delimitation among lanes limits the side-by-side accident risk. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. In a previous paper authors proposed a theoretical approach to evaluate turbo-roundabouts capacity founded on gap acceptance theory. In particular, …

Assessing the environmental impact exerted by roads in “operative” conditions - a Highway case-study

Estimation of measures of effectiveness (MOE) for the C- Roundabouts

The C-roundabout (cyclist roundabout) is a new multi-lane roundabout designed to improve the safety of cyclists at and make multi-lane roundabouts more cyclist-friendly. The geometric layout of C-Roundabouts allows the decrease of the vehicle speeds through the roundabout to around 30 km/h. The rare C-roundabout installations so far implemented in the world have not allowed analysing the capacity by means empirical data. In the light of this considerations, the main objective of the paper is to give a theoretical closed-form model for evaluation the measures of effectiveness “MOE” (capacity, delay, queues) of the C-Roundabouts.

A model for evaluating the environmental and functional benefits of “innovative” roundabouts

This study looks at the singling out of a multi-parameter criterion for choosing conventional or innovative roundabout layouts, by taking functional, environmental and economic aspects into consideration. The performances of three conventional roundabouts (with different lane number at entries and through the ring), turbo-roundabouts and roundabouts with right-turn bypass lane on all the arms (flower roundabouts) have been compared in terms of vehicle delays and pollutant (carbon dioxide, nitrogen oxides, particle pollution (PM10 and PM2.5)) emissions. By means of closed-form capacity models and with the help of COPERT IV© software, several traffic simulations have been carried out, referre…

LCA of Different Construction Choices for a Double-Track Railway Line for Sustainability Evaluations

The international commitment to achieve carbon neutrality in the next few decades has oriented human activities towards the preservation of natural and non-renewable resources. In this context, a great research effort has been devoted to the search for sustainable solutions for the infrastructure construction sector, based on a thorough assessment of the environmental impact (EI). In this regards, Life Cycle Assessment (LCA) is considered one of the main components of Environmental Impact Assessment (EIA) and, for a comprehensive analysis, all the costs incurred by stakeholders during the useful life of the infrastructure should also be taken into account, applying the Life Cycle Cost (LCC)…

Traffic Flow Variables Estimation: An Automated Procedure Based on Moving Observer Method. Potential Application for Autonomous Vehicles

Abstract The estimation of traffic flow variables (flow, space mean speed and density) plays a fundamental role in highways planning and designing, as well as in traffic control strategies. Moving Observer Method (MOM) allows traffic surveys in a road, or in a road network. This paper proposes a novel automated procedure, called MOM-AP based on Moving Observer Method and Digital Image Processing (DIP) Technique able to automatically detect (without human observers) and calculate flow q, space mean speed vs and density k in case of stationary and homogeneous traffic conditions. In order to evaluate how reliable is the MOM-AP, an experiment has been carried out in a segment of one two-lane si…

A new type of railway monoblock sleeper

A railway sleeper is the structural element which transversally connects the two rails by means of fastening components, thus ensuring its gauge. Its additional function is to firmly secure the track to the ballast and to distribute the loads transferred from railway carriages to the ballast. One of the most important parameters in the characterisation of performances given by railway sleepers is represented by their lateral resistance to the sliding: the higher its value increases, the better the track stability becomes, thus reducing the frequency of maintenance interventions necessary to keep the superstructure efficient. This article focuses on the performance profile of an innovative r…

Piezoelectric energy harvesting from raised crosswalk devices

This paper presents the main characteristics of an experimental energy harvesting device that can be used to recover energy from the vehicular and pedestrian traffic. The use of a piezoelectric bender devices leads to a innovative approach to Henergy Harvesting. The study focuses on the definition and specification of a mechanical configuration able to transfer the vibration from the main box to the piezoelectric transducer. The piezoelectric devices tested is the commonly used monolithic piezoceramic material lead-zirconate-titanate (PZT). The experimental results estimate the efficiency of this device tested and identify the feasibility of their use in real world applications. The results…

Applicazioni dell’image processing nel campo delle infrastrutture viarie. Il monitoraggio della viabilità in esercizio

Nel settore delle infrastrutture di trasporto, si stanno sempre più sviluppando specifiche tecniche di rilievo automatico, ad alto rendimento, utilizzate per il monitoraggio dei parametrici caratteristici del traffico e di quelli geometrici dell’infrastruttura. Di particolare interesse per la loro semplicità, flessibilità d’uso, economia ed affidabilità sono le tecniche basate sull’image processing, che prevedono l’impiego sinergico di un sistema di monitoraggio e di elaborazione delle sequenze video registrate con strumentazioni digitali o analogiche. In questo ambito, le molteplici esperienze di ricerca già maturate hanno dimostrato la versatilità di tali procedure in numerose applicazion…

Improving the sustainability of transportation: environmental and functional benefits of right-turn by pass lanes at roundabouts

The functional performances of conventional roundabouts (single-lane and multi-lane) and innovative roundabouts (spiral, flower, C and turbo) can be improved through right-turn bypass lanes controlled by stop, yield or free-flow signs. The article presents evaluations of the emissions of air pollutants (carbon dioxide, nitrogen oxides, particle pollution (PM10 and PM2.5)), fuel consumption and construction, management, energetic and environmental costs in roundabouts without or with bypass lanes (controlled by stop, yield or free-flow). The suggested methodology has a general character and can be applied as a multi-parametric criterion for choosing road intersections, although, in the prese…

Estimation of air pollutant emissions in flower roundabouts and in conventional roundabouts

Abstract The road pollutant emissions, above all in urban context, are correlated to many infrastructural parameters and to traffic intensity and typology. The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety, like the flower roundabouts (in which right-turn manoeuvres do not conflict with the circulating flow). The main objective of this paper is to propose a model for the estimation the capacity, delay, levels of service and the pollutant emissions into flower roundabouts. A comparative analysis between conven…

Analisi di funzionalità delle rotatorie a fiore

Le attività di ricerca inerenti la geometria dei nodi viari, svolte soprattutto in Enti di ricerca europei, in tempi relativamente recenti hanno consentito di ideare nuove tipologie di intersezioni stradali che presentano un indubbio interesse, soprattutto in termini di funzionalità e di sicurezza della circolazione. Tra le soluzioni più interessanti si annoverano gli schemi affini alle tradizionali rotatorie come ad esempio le rotatorie a spirale, le turbo rotatorie e le rotatorie a fiore. Pur trattandosi di soluzioni con circolazione rotatoria, in genere negli schemi di nuova concezione le modalità di regolamentazione dei flussi veicolari risultano assai diverse rispetto a quanto avviene …

Geometria e funzionalità delle corsie di bypass per la svolta a destra

OBIETTIVO PUNTATO SULL’INCREMENTO DELLA CAPACITA' DELLE INTERSEZIONI A ROTATORIA CONVENZIONALI E INNOVATIVE ATTRAVERSO L’IMPIEGO DEI BYPASS PER LA SVOLTA A DESTRA, TIPOLOGIA DI INFRASTRUTTURA STRADALE I CUI PRINCIPALI CRITERI COMPOSTIVI E LE CUI PROCEDURE DI DIMENSIONAMENTO DEGLI ELEMENTI MODULARI VENGONO DESCRITTI NEL DETTAGLIO DAGLI AUTORI. PRESI IN ESAME, ANCHE I PIù RECENTI MODELLI MATEMATICI PER LA STIMA DELLA CAPACITà DELLE CORSIE DI BYPASS E DELLA CAPACITà SEMPLICE DEGLI INGRESSI IN ROTATORIA.

Dalla relazione Possenti ai primi provvedimento postunitari per il completamento e l'adeguamento della rete stradale siciliana

La pianificazione stradale in Sicilia prima dell’Unità di italia

Mono and Stereoscopic Image Analysis for Detecting the Transverse Profile of Worn-Out Rails

AbstractThe purpose of this paper is to suggest a new procedure for reconstructing the transverse profile of rails in operation by means of image-processing technique. This methodological approach is based on the “information” contained in high-resolution photographic images of tracks and on specific algorithms which allow to obtain the exact geometric profile of the rails and therefore to measure the state of the rail-head extrados wear. The analyses and the results concern rails taken from railway lines under upgrading by means of mono- and stereoscopic methods which are appropriate to be employed in laboratory applications or in high-efficiency surveys in situ.

Calculation of turbo- roundabouts with slip lanes

A turbo roundabout is a particular type of roundabout where all lanes are bounded by traffic signs and by non-mountable curbs installed at entering and circulating lanes. Turbo roundabouts also have a very particular shape to accomplish the splitting of traffic streams and to prevent cars weaving through. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. Only in some traffic conditions, turbo roundabouts can offer higher capacities than conventional double-lanes roundabouts, so if more capacity must be guarantee a bypass lane can be added t…

EFFETTI LOCALI E D’AREA GENERATI DALLE MISURE DI MODERAZIONE DELLA VELOCITÀ. UN BILANCIO DA CONSIDERARE IN SEDE DI PIANIFICAZIONE

Le strategie finalizzate al miglioramento della sicurezza stradale si muovono, in generale, secondo due finalità distinte: - da un lato, di contenere la gravità delle conseguenze di comportamenti di guida a rischio attraverso l’installazione di dispositivi utili per limitare i danni agli occupanti del veicolo in caso di urto; - d’altro lato, di impedire (o quanto meno scoraggiare) comportamenti di guida imprudenti attraverso l’adozione di misure idonee ad allertare gli utenti e ad indurli a comportamenti non trasgressivi. Alla seconda finalità sono riconducibili i dispositivi di moderazione della velocità, i quali, agendo sui comportamenti di guida, mirano a prevenire l’insorgere di inciden…

A model to evaluate heavy vehicle effect in motorway traffic flow

Highway operating conditions are also determined by interactions between passenger cars and heavy vehicles in the flow. Therefore, a suitable model which describes and predicts the heavy vehicle effect can be useful to achieve more realistic criteria to evaluate the Level of Service (LOS) for infrastructures in the uninterrupted flow. After reviewing briefly the models available in literature to take account of the effects on operating conditions due to heavy vehicles, the paper examines some traffic data analysis of the Italian A22 motorway and later presents a closed-form traffic model for heavy vehicles via the queuing theory. Some applications of this model are displayed for operational…

High Performance Bi-Block Sleeper for Improvement the Performances of Ballasted Railway Track

Abstract This article focuses on the performance of an innovative railway sleeper, recently patented in Italy and called “HP-BB” (High Performance Bi-Block sleeper), under different efficiency conditions of the ballast. The research is carried out through a comparative assessment of traditional mono- and bi-block sleepers, evaluating the lateral resistance of the single sleeper thought as independent of the other constituents of the track.

La via Libertà di Palermo

A Stochastic Decision Process Model for Optimization of Railway and Tramway Track Maintenance by means of Image Processing Technique

One of the key targets for an efficient transport network management is the search for proper maintenance policies to guarantee acceptable safety and quality standards in the travel and to optimize available resource allocation. Methodologically, the proposed model presented in this paper uses the stochastic dynamic programming and in particular Markov decision processes applied to the rail wear conditions for the railway and tramway network. By performing the integrated analysis of the classes of variables which characterize the rail quality (in terms of safety), the proposed mathematical approach allows to find the solutions to the decision-making process related to the probability of det…

Infrastrutture ferroviarie, metropolitane, tranviarie e per ferrovie speciali. Elementi di pianificazione e di progettazione.

Il volume presenta i criteri fondamentali di progettazione geometrico-funzionale delle infrastrutture per i sistemi di trasporto a guida vincolata tra i quali si annoverano sia quelli extraurbani, come le ferrovie convenzionali e ad alta velocità, sia quelli urbani come le metropolitane (“pesanti”, “leggere” ed “automatiche”), le tranvie ed i people movers. Per ogni sistema di trasporto sono descritti gli orientamenti tecnici – progettuali e costruttivi - ritenuti più rilevanti, le peculiarità trasportistiche (ad esempio i valori di capacità) ed i principali riferimenti normativi adottati per la definizione dei singoli elementi compositivi del tracciato delle linee, delle stazioni e delle f…

A Logic Fuzzy Model for Evaluation of the Railway Station’s Practice Capacity in Safety Operating Conditions

Abstract The practice capacity of a railway junction depends, in addition to the effective operation’s conditions, by the potential risk factors related to the design plan of the railway station. With the aim of an approach based on the “fuzzy sets” it is possible to determine the numeric value of the practice capacity by the logic - qualitative relations between the features of the railway junction and the potential risk factors. This methodology permits to try out the absolute value of a suitable vector β, (less then the unit) for the utilization of the theoretic capacity in conditions of maximum reliability of the system related to the aspect of safety (technique “fail safe”).

Environmental, functional and economic criteria for comparing “target roundabouts” with one- or two-level roundabout intersections

The article describes a criterion based on functional, environmental and economic aspects for comparing conventional roundabouts with innovative one- or two-level roundabouts. We compared the performances of eight roundabout types, differing in geometric layout, number of lanes and traffic flow regulation from each other, with regard to vehicle delays and CO2, NOx, PM2.5 and PM10 pollutant emissions. Recently-designed roundabouts - target roundabouts and flyover roundabouts - have also been studied for their undoubted practical interest. By means of closed-form capacity models and CORINAIR methodology, several traffic simulations were carried out to examine a typical annual traffic demand c…

Il concetto di sicurezza stradale, evoluzione e strumenti di valutazione

Il volume illustra il tema della sicurezza stradale nelle sue molteplici dimensioni e in maniera trasversale, con uno specifico approfondimento per la Sicilia, mettendo a disposizione un'ampia selezione di informazioni qualitative e quantitative per specifiche analisi sulla sicurezza stradale, utili ai policy maker per intraprendere azioni di programmazione a livello locale. L'Italia registra un elevato tasso di mortalità rispetto alla media europea, una lenta riduzione del numero di vittime per incidente stradale e marcati divari territoriali. Nel contesto nazionale questo studio descrive poi l'evoluzione del fenomeno dell'incidentalità in Sicilia nell'ultimo decennio, individuando puntual…

Turbo-Roundabouts: a Model to Evaluate Capacity, Delays, Queues and Level of Service

A turbo roundabout is a particular type of roundabout where entering and circulating lanes are bounded by traffic signs and by non-mountable curbs. The physical separation between lanes, both at entries and on the ring, helps to prevent side collisions crossing the roundabout. The main advantages of turbo roundabouts are: i) reduction in the number of potential conflict points; ii) lower speed of vehicles passing through the intersection; iii) safety conditions at the intersection due to lower risk of side-by-side accidents. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestri…

Cost-benefit analysis of road safety measures

Road accidents represent one of the most serious problems faced by the Ministries of Public Health in the World. In Italy for example, in the year 2007 there were almost 330, 000 injuries and 5, 131 fatalities; 230, 871 crashes in all which resulted in an estimated € 30.4 billion financial loss, corresponding to 2% of GDP. In 1999 the National Road Safety Plan (NRSP), among other things, funded the requalification of several unsafe road infrastructures at higher risk of accidents. Unlike other infrastructure investment plans, NRSP usually requires: i) specific safety analysis of crash history to identify the critical road; ii) proactive action, e.g. RSAs and RSARs; iii) before-after acciden…

An international review on one and two level innovative unconventional intersection and interchange.

The research on road intersection and interchange has recently allowed to design innovative one and two level unconventional layouts (UIIDs) which are of undoubted interest, especially in terms of traffic functionality and safety. The main objective of the paper is to discuss the geometric layouts, the principal advantages and the disadvantages, in terms of cost, safety, performances of the most interesting UIIDs, like two-level signalized intersection (TLSI), single-point urban interchanges (SPUI), center-turn overpass (CTO), echelon interchange (EI), Crossover Diamond interchanges (DCD), Upstream Signalized Crossover Intersection (USC), Median U-turn Intersection (MUT), “Target”, “Flower”…

Nuovi schemi geometrici di intersezioni stradali per l’incremento della capacita e della sicurezza

The design of waiting and storage areas to improve the efficiency of the marine intermodal terminals

The correct sizing of storage areas in the port areas is aimed to optimizing the management of intermodal transport and to ensure efficiency and functionality to the entire port system. In this paper is proposed a simulation model for design the port storage areas taking into account many parameters like: the service time, the randomness of the arrivals process, the storage capacity in terms of TEU that can be stored (and handled) in the unit of time. The capacity of the terminal warehouse is determined by the interrelation between fixed and static parameters in the short period which are: i) the extension of the storage area; ii) the height of the overlapping batteries of container (define…

Environmentally appraising different pavement and construction scenarios: A comparative analysis for a typical local road

Abstract The aim of this work is to carry out a comparative analysis of environmental impacts for different scenarios of a typical local road. Life Cycle Assessment (LCA) is the modeling tool used to quantify and characterize comparative environmental impacts. In carrying out this specific application of the LCA, different road construction techniques were considered with regards to the whole structure and compared in order to identify the best alternative in terms of environmental sustainability. So far, in fact, typical LCA frameworks of roads have focused on recycled materials for pavement layers only, thus neglecting study of the materials used in the embankment or in the subgrade. In t…

Calculation of Turbo-Roundabouts with Slip Lanes

A turbo roundabout is a particular type of roundabout where all lanes are bounded by traffic signs and by non-mountable curbs installed at entering and circulating lanes. Turbo roundabouts also have a very particular shape to accomplish the splitting of traffic streams and to prevent cars weaving through. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. Only in some traffic conditions, turbo roundabouts can offer higher capacities than conventional double-lanes roundabouts, so if more capacity must be guarantee a bypass lane can be added t…

La prima pianificazione postunitaria della rete ferroviaria della Sicilia

Gestione e diagnostica della sovrastruttura ferroviaria. Un caso studio: la linea Palermo-Messina

La via Libertà a Palermo

Embedding “roadside equipment” in the environmental assessment of transportation system: the case of safety barriers

The work arises from the consideration that the environmental impact of a road cannot be limited to the analysis of its constituent materials, even if correctly analyzed in their life cycle. In fact, a given road not only consists of the pavement and subgrade, but also includes several different components and accessories (e.g., road marking, drainages, safety barriers, etc.) that contribute to set a road infrastructure in operative condition. As a matter of fact, only limited attention has been paid in the scientific literature to roadside components, unlike pavement and traffic flow. In the present work, the environmental burden of one of these components, i.e., the safety barrier has bee…

Sistemazione e messa in sicurezza della SP di Pantelleria

Estimation of Air Pollutant Emissions in “Turbo” and in Conventional Roundabouts

The road pollutant emissions, above all in urban context, are correlated to many infrastructural parameters and to traffic intensity and typology. The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety, like the turbo roundabouts (in which right-turn manoeuvres do not conflict with the circulating flow). The main objective of this paper is to propose a model for the estimation the performances and the pollutant emissions into turbo roundabouts. A comparative analysis between conventional roundabout and turbo round…

STRATEGIE E CRITERI PROGETTUALI PER LA CONVERSIONE DI LINEE FERROVIARIE DISMESSE IN PERCORSI VERDI

Il progressivo incremento della mobilità privata, verificatosi a partire dalla seconda metà del secolo scorso nei Paesi occidentali, e in particolare in Italia, ha determinato la chiusura al traffico di molte linee ferroviarie secondarie ormai scarsamente utilizzate e, dunque, poco remunerative per gli Enti proprietari e/o gestori. Il patrimonio viario dismesso trova oggi una possibile occasione di riqualificazione funzionale mediante la conversione delle linee ferrate in percorsi verdi (greenways) dedicati alla cosiddetta “mobilità dolce” di tipo ciclopedonale; ciò in ragione delle seguenti caratteristiche: i) separazione del sedime ferroviario dalla rete stradale ordinaria; ii) ridotto nu…

LE SOVRASTRUTTURE STRADALI IN CONGLOMERATO BITUMINOSO. RECENTI INNOVAZIONI PER LA TUTELA AMBIENTALE.

L’attuale patrimonio stradale Italiano è costituito da 6.500 Km di Autostrade, 46.500 Km di strade Statali, 115.222 Km di strade provinciali e da 312.149 Km di strade comunali extraurbane, per un totale di 480.804 Km; a tale valore, va sommato lo sviluppo della viabilità urbana, non facilmente determinabile. Nel corso degli ultimi trenta anni, si è assistito all’incremento del traffico di veicoli pesanti che, unitamente alla diffusa tendenza di viaggiare in sovraccarico, determina il rapido deterioramento delle pavimentazioni stradali, soprattutto per accumulo di deformazioni permanenti; le conseguenti attività manutentive, ordinarie e straordinarie, necessarie per ripristinarne la funziona…

STRATEGIE DI BREVE PERIODO PER UNA MOBILITÀ SOSTENIBILE IN AMBITO URBANO.

L’inquinamento atmosferico desta particolari preoccupazioni soprattutto nelle aree urbane, sia per l’intensa produzione di inquinanti, con frequenti episodi acuti, sia per il cospicuo numero di cittadini esposti al rischio di danni alla salute. Inoltre, all’interno dei centri urbani, le emissioni di inquinanti diffuse dagli scarichi dei veicoli (CO, NOX, COV, PM10, IPA, ecc.) avvengono in condizioni particolarmente sfavorevoli per le condizioni operative del deflusso veicolare, che risulta interrotto a causa della presenza di intersezioni (semaforizzate e non) particolarmente ravvicinate tra loro, e per l’edificato che inibisce la rapida dispersione dei gas di scarico in atmosfera. La netta…