A közlekedésépítési szakterület mérnöki és tudományos folyóirata. ISSN
11. szám
11
Bejegyzés

Nemzetközi szemle: Január

Aszfalt keverékek teljesítmény alapú előírásai. Az útügyi gyakorlat összefoglalása

Performance Specifications for Asphalt Mixtures. A Synthesis of Highway Practice
Szerző(k):
L. M. McCarthy, J. Callans, R. Quigley, S. V. Scott
Villanova University, Hill International, Inc., USA
Terjedelem: 306 oldal

Asphalt mixtures are typically designed within a given gradation band to meet a set of volumetric properties at a given laboratory compaction effort. This project will document the state of the practice in performance specifications for asphalt mixtures and their use with traditional volumetric properties. Performance specifications can be performance-related and/or performance based. Asphalt mixtures include both hot mix asphalt and warm mix asphalt, and are produced at a plant and may include mixtures that have been modified with recycled materials. Volumetric properties may not provide optimum performance for mixtures that include recycled materials and/or certain types of modifiers. Some agencies have investigated performance specifications for asphalt mixtures. These specifications typically include tests for rutting and cracking. Other agencies are investigating mechanistic properties (i.e., dynamic modulus) in conjunction with implementing mechanistic-empirical pavement design. In addition, certain areas may require performance tests to address specific requirements such as studded tire wear and moisture susceptibility tests. This synthesis documents the performance tests used in conjunction with volumetric properties for mixtures. Performance tests are intended to extend service life by guiding material selection (i.e., asphalt binder and aggregate) and proportions (i.e., asphalt content and gradations). The results will benefit government agencies, researchers, and the road building industry by providing guidance on making better use of recycled materials, while also providing better performing and more cost-effective asphalt mixtures for specific applications. The synthesis provides examples of engineering tools used in the development and implementation of performance specifications for asphalt mixtures, examples of the contents of performance-based specifications (PBS) currently used or in development, information on test program implementation and research related to PBS for asphalt mixtures, and the reported benefits and challenges with implementing PBS. Information for this report was acquired through a literature search, a survey of the use of performance specifications for asphalt mixtures, and seven case examples from six state departments of transportation, and the city of Edmonton, Alberta, Canada.

 

Mellékutak kerékpáros biztonságának javítása

Improving safety for people who cycle on rural roads
Szerző(k):
M.Trotter, P. Kortegast, J. Beetham, C. Bowie, J. Burton, J. Thomas
Opus International Consultants Ltd., NZ Transport Agency, New Zealand
Terjedelem: 69 oldal

This study aimed to determine how to cost-effectively improve safety for people who cycle on low-volume rural roads in New Zealand. Following a literature review and Crash Analysis System consultation, two treatments were identified for on-road trial: 1) Advisory signs on passing distance and 2) A 2-1 layout (adapted to the New Zealand context). The latter became a shared space arrow treatment after the 2-1 component was discontinued for safety reasons. The key performance measures of vehicle approach speed, vehicle passing distance, and bicycle speed were measured using an integrated suite of instrumentation on four bicycles. No significant differences were found between either of the treatments and baseline on any of these measures; however, Metrocount data indicated that there was a significant 2km/h speed reduction in the signage treatment area. The instrumentation data provided baseline measures of approach speed (76.8km/h), passing distance (2.12m) and bicycle speed (23.67km/h). Recommendations for future work on cyclist safety on low-volume rural roads include the development of standardised share the road signage, the further adaptation of the 2-1 design to the New Zealand context, the implementation of a robust communication and engagement strategy for innovative research, and baseline data collection to better inform countermeasures.

 

Bitumenek teljesítmény előírásai és vizsgálatai Ausztráliában és a világ többi részén

Review of Australasian and Overseas Specifications and Performance Tests for Bitumen
Szerző(k):
Y. Choi
Austroads, Australia (a letöltéshez ingyenes regisztráció szükséges)
Terjedelem: 57 oldal

This report describes a literature review on the bitumen/binder specifications and test methods used in Australasia, USA, Europe and South Africa. The project investigated whether the Australian and New Zealand bitumen specifications are adequately related to performance, and appropriate for evaluating the current generation of bitumens. The Australian bitumen specification (AS 2008) and PMB specification (AGPT/T190) were found to be able to rank the performance of binders at high road temperatures (e.g. 60 °C), and also could account for regional climatic variations. Concerns have been raised in New Zealand about the New Zealand bitumen specification (NZTA M1) as bitumens are increasingly being imported into the country. As a result of these concerns, new bitumen/binder specifications have been under development in New Zealand. Preliminary New Zealand validation studies appear to suggest that the new specifications may be appropriate for evaluating the performance of asphalt and sprayed sealing grade binders in New Zealand. The current Australian and the proposed New Zealand bitumen specifications were not immediately interchangeable in their current forms, and thus further studies would be required if a common specification is to be developed for the two countries in the future. A review of international development work into performance-based specifications indicated that traditional binder tests (e.g. viscosity at 60 °C and penetration at 25 °C) were generally considered suitable for ranking the performance of bitumens. A number of potential performance-based tests are currently under development in various countries to characterise the properties of PMBs. The results of this research are expected to provide useful information when the Australian and New Zealand PMB specifications are updated.

 

Útburkolati jelek anyagainak skandináv minősítési rendszere

Nordic certification system for road marking materials
Szerző(k):
C. Fors, T. C. Johansen, S.-O. Lundkvist
VTI, Ramböll, Sweden
Terjedelem: 47 oldal

A Nordic certification system for road marking materials was introduced in 2015. The system is based on documented performance measurements of material samples applied on test fields on public roads.
From 2016, the certification system includes both flat (type I) and structured/profiled (type II) markings. Material tests are carried out at two test sites: one in Sweden and one in Denmark. The tests fields are situated on public roads and the tested materials are thus exposed to real traffic conditions and to weather conditions representative for the Nordic countries. The materials are followed up by performance measurements during one or two years. The certification includes requirements on coefficient of retroreflected luminance RL under dry and wet conditions, luminance coefficient under diffuse illumination Qd, friction and colour coordinates. The number of wheel passages are measured at the test sites annually. The certification system includes material identification, which allows for future material sampling and analysis. The certification system is based on the European standards EN 1824 Road marking materials – Road trials, EN 1436 Road marking materials – Road marking performance for road users, and EN 12802 Road marking materials – Laboratory methods for identification. The report describes the certification system and how it is applied in the Nordic countries. Procedures and methods that are used for application of materials and performance measurements are specified.

 

Valós idejű nagy tömegű használói információ és technológia szerepe az utazási információ és a hálózati hatékonyság támogatásában

The role of real-time crowdsourced information and technology in supporting traveller information and network efficiency
Szerző(k):
D. Harris, D. Smith, C. O’Neil, J. Severinsen
Abley Transportation Consultants Limited, NZ Transport Agency, New Zealand
Terjedelem: 116 oldal

Crowdsourcing is the practice of engaging the services of a large and undefined group of people (the ‘crowd’) to provide information or input into a particular task or activity. In transport applications, crowdsourcing has the potential to meet information needs across all modes for a range of purposes, including the provision of traveller information, and supporting transport network operations, road safety and asset management. This research investigates the role of crowdsourcing in New Zealand as an input to inform traveller information systems and in doing so supporting road network efficiency outcomes. The primary purpose of this research is to identify the strategic, legal and policy considerations necessary to enable road controlling authorities and government agencies to lead or support crowdsourced data initiatives. These considerations include the management of privacy, safety, data collection, storage and retrieval, the use of incentives, data quality assurance and organisational barriers to new technologies and data collection methods. The outputs of the research include practical recommendations regarding potential applications of crowdsourcing in the transport sector, the role of NZ Transport Agency and other road controlling authorities in supporting a crowdsourcing data ecosystem, and the technical requirements for crowdsourcing data to support traveller information systems.

 

A hídpálya görbület változásának precíziós mérése pályacsere esetén

Precision Monitoring of Bridge Deck Curvature Change During Replacement
Szerző(k):
M. K. Khandani
University of Maryland, USA
Terjedelem: 50 oldal

This project was focused on development and deployment of a system for monitoring vertical displacement in bridge decks and bridge spans. The system uses high precision wireless inclinometer sensors to monitor inclinations at various points of a bridge deck. The inclination data is fed into a mathematical model which calculates vertical displacement. As a specific goal, this project was intended to monitor change in vertical displacement and curvature of a bridge deck during the deck replacement process. Wireless inclination/temperature sensors were developed and thoroughly tested in laboratory environment. Mathematical curvature calculation methods were used to convert inclination data into vertical displacement. Wireless precision inclination/temperature sensors were deployed on a bridge close to Pocomoke City in Maryland, which underwent deck replacement from January until August 2015. The sensor revealed that, temperature change could lead to z changes in inclination of bridge girders. The changes in inclination would lead into temperature induced vertical displacement of a bridge deck. As a result, comparing change in displacement of bridge deck before and after deck replacement is not meaningful unless temperature effects are characterized. The study also revealed shortcoming of surveying, being used to find change in curvature of a bridge, because unless two surveys for a bridge deck are taken place at the same time, their results cannot be directly compared. The method based on wireless inclinometer sensors characterizes the effect of temperature and therefore, it separates contribution of temperature from the change in the displacement caused by deck replacement.

 

Autópálya esemény-kezelési programok gyakorlata és szakirodalmi áttekintése

Review of Literature and Practices for Incident Management Programs
Szerző(k):
Texas A&M Transportation Institute, USA
Terjedelem: 50 oldal

The project team examined project evaluations, best practice summaries, and synthesis documents, and derived a summary of key elements of programs to speed the time to find and clear stalled vehicles and crashes from freeway shoulders and main lanes. The key questions about these programs (known generically as incident management) include the following: Who operates the program? What are the key equipment and procedural elements? How is the program funded? How much of the road network is covered and for what times/days? What are the incident management program institutional arrangements and interjurisdictional operating practice memoranda? What are the benefits and costs?
This literature review summarizes key practice elements that describe a comprehensive traffic incident management (TIM) program and then compares those characteristics to the significant Texas programs. The goal is to describe the current state of the practice on a few key items as the beginning point of discussion about any additional public policy guidance or legislation needs.

 

A közlekedés 2045 után – a szállítás újraértelmezése: technológia, alapvető újítások és a közlekedés jövője

Beyond Traffic 2045 Reimagining Transportation: Technology, Disruptive Innovation, and the Future of Transportation
Szerző(k):
B. Barami, C. Merrefield
Office of Strategic Initiatives for Research and Innovation, U.S. Department of Transportation, John A. Volpe National Transportation Systems Center, USA
Terjedelem: 25 oldal

Transportation innovation is happening at an unprecedented pace. We’re seeing advances in communication, connected automation, data, navigation, robotics, and smart cities that just a few years ago would have seemed like pure science fiction. We’re entering a transportation landscape rich with possibility, and full of challenges. The next 10 years could bring more change to transportation and to the transportation workforce than we saw over the past century. A nation on the move must be a nation that is looking forward. In 2015, U.S. Transportation Secretary Anthony R. Foxx released Beyond Traffic 2045: Trends and Choices, a comprehensive report on the major forces impacting our nation’s transportation systems. The report frames critical policy questions by identifying trends that are shaping our transportation future. We’re poised to see major changes in car ownership, freight movement, population growth patterns, urbanization, vehicle miles traveled, and transportation-focused technologies. We’re going to face significant challenges related to aging infrastructure, energy use, highway safety, network congestion, rising greenhouse gas emissions, and more powerful weather events. The U.S. must always have a safe, reliable transportation system that can compete globally, but that won’t be possible unless we answer some big questions. How do we build and pay for infrastructure and capacity needs? How can we do a better job maintaining infrastructure? What strategies can we use to reduce emissions? How can technology enhance safety and efficiency? How do we ensure our transportation system connects people to economic opportunities?

 

Okos telefon alkalmazások hatása az utazás választásra: gyakorlat és politika

Smartphone Applications to Influence Travel Choices: Practices and Policies
Szerző(k):
S. Shaheen, A. Cohen, I. Zohdy, B. Kock
Booz Allen Hamilton Inc., UC Berkeley, USA
Terjedelem: 90 oldal

This primer provides an overview of current practices in this emerging field and looks toward the future in the evolution and development of smartphone applications for the transportation sector. The primer provides an introduction and overview smartphone applications (known as “apps”); discusses the background, evolution, and development of smartphone apps; reviews the types of smartphone applications promoting transportation efficiency and congestion reduction; discusses transportation apps and their impacts on traveler behavior; examines current challenges; and concludes with guiding principles for public agencies.

 


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