Context-sensitive design in transportation infrastructure: relating tire/pavement noise with wearing course characteristics

A design can be defined as context-sensitive when it achieves effective technical and functional transportation solutions, while preserving and enhancing natural environments and minimizing impacts on local communities. Traffic noise is one of the most critical environmental impacts of transportation infrastructure and it affects both humans and ecosystems. Tire/pavement noise is caused by a set of interactions at the contact patch and it is the predominant source of road noise at the regular traffic speeds. Wearing course characteristics affect tire/pavement noise through various mechanisms. Furthermore, acoustic performance of road pavements varies over time and it is influenced by both aging and temperature. Three experimentations have been carried out to evaluate wearing course characteristics effects on tire/pavement noise. The first study involves the evaluation of skid resistance, surface texture and tire/pavement noise of an innovative application of multipurpose cold-laid microsurfacing. The second one involves the evaluation of the surface and acoustic characteristics of the different pavement sections of the test track of the Centre for Pavement and Transportation Technology (CPATT) at the University of Waterloo. In the third study, a set of highway sections have been selected in Southern Ontario with various types of pavements. Noise measurements were carried out by means of the Statistical Pass-by (SPB) method in the first case study, whereas in the second and in the third one, Close-proximity (CPX) and the On-Board Sound Intensity (OBSI) methods have been performed in parallel. Test results have contributed to understand the effects of pavement materials, temperature and aging on tire/pavement noise. Negligible correlation was found between surface texture and roughness with noise. As a general trend, aged and stiffer materials have shown to provide higher noise levels than newer and less stiff ones. Noise levels were also observed to be higher with temperature increase

A Study on Texture and Acoustic Properties of Cold Laid Microsurfacings

AbstractSlurry microsurfacing is an economical maintenance intervention that provides effective skid resistance and surface evenness in a thin layer, thus improving the road safety. Researchers aimed to develop an innovative application of slurry seal, capable of gathering in a single material some technical solutions for various functional and environmental aspects. The purposes of this intervention are: restoring skid resistance, sealing surface cracking, reducing tire/pavement noise, adding crumb rubber from tires as a recycling material and reducing atmospheric emissions using the cold technique. A 3D laser scanner device has been used to evaluate the surface texture and analyze the roughness parameters

An Infrastructure Fragmentation Index for Assessing Landscape Fragmentation Due to Transportation Infrastructure

Landscape fragmentation is the phenomenon of breaking up natural areas into smaller, more isolated units. The present work describes a methodology for evaluating the impact of both new and pre-existing transportation infrastructures by means of land cover maps. It enables quantifying the “pressure” on natural areas in terms of any further reduction in suitable habitat units based on the type of infrastructure and land cover elements. The proposed Infrastructural Fragmentation Index (IFI) assesses landscape fragmentation, taking into account both the number and connectivity of natural areas, which are rendered in clusters. The effects of defragmentation measures, such as wildlife crossings, are evaluated in terms of the consequent reduction in the pressure from the infrastructure. A case study has been analyzed in order to evaluate the fragmentation effects due to a new motorway in Lombardy (Italy), using CLC2000 and a GIS. Three scenarios have been studied: in the absence of the new infrastructure, and in its presence without and with the addition of wildlife crossings

La valutazione della leggibilità della segnaletica verticale e degli elementi di arredo stradale tramite Mobile Eye

Vertical signs shall be located on the road according to a proper signalling plan, capable of providing relevant information to drivers in a harmonious, integrated and effective way. To achieve these targets, it is essential to investigate how road users look and perceive vertical signs while driving. For this purpose, an experimental research project was carried out onsite which involved 22 road users, driving on a road stretch comprising different types of vertical signs. By the use of an innovative eye-tracking device, capable of tracking human eye and its movements, it was possible to continuously record the glance aiming point of each road user, obtaining a detailed analysis of driver/ vertical signs interaction.La segnaletica verticale deve essere dislocata sulla strada secondo un piano di segnalamento appropriato, in grado di fornire ai conducenti dei veicoli le opportune informazioni in modo armonico, integrato ed efficace. Per raggiungere questi obiettivi è indispensabile indagare come gli utenti guardano e considerano i segnali verticali durante la guida. A tal fine è stata realizzata una sperimentazione in sito che ha coinvolto 22 conducenti, i quali hanno percorso in auto un tratto di strada comprendente diverse tipologie di segnali verticali. Attraverso l’utilizzo di un’innovativa strumentazione eye tracking, in grado di tracciare l’occhio umano e i suoi movimenti, è stato possibile registrare in continuo il punto di mira dello sguardo di ogni utente, ottenendo un’analisi dettagliata dell’interazione conducente/segnaletica verticale

TEMPERATURE AND AGING EFFECTS ON TIRE/PAVEMENT NOISE GENERATION IN ONTARIAN ROAD PAVEMENTS Professor, Canada Research Chair in Sustainable Pavement and Infrastructure Management

ABSTRACT 2 Tire/pavement noise is caused by a complex set of interactions in the contact patch. 3 Managing pavement surfaces and materials has been an effective strategy for noise 4 mitigation, because it is often possible to act at the source of the noise. Since traffic noise is a 5 public concern, due to the effects on heath and the economy of a country, it is crucial to 6 understand the acoustic performance of road pavements through continuous monitoring, 7 because their acoustic properties may diminish over the time. Overall, the results show that sound intensity and sound pressure level raise when the 18 age increases, while temperature performs a minor influence. Also, the results demonstrate 19 that sound intensity and sound pressure levels have a significant variation depending on the 20 type of pavement. Finally, good correlation between CPX and OBSI methods was observed