Nemzetközi szemle: Május
Sebesség harmonizáció – tervezési sebesség és tényleges sebesség
Speed Harmonization—Design Speed vs. Operating Speed
Szerző(k):
Z. Jiang, K. Jadaan, Y. Ouyang
University of Illinois USA
Terjedelem: 92 oldal
When the actual operating speed on the roads exceeds the design speed, which is common on rural highways, the roadway design may become problematic from a safety point of view. This report presents a new methodology that summarizes the relationship between design speed and operating speed, as well as the safety impacts of various geometric elements. A comprehensive literature review and a series of interviews with Illinois county engineers were conducted to summarize the current roadway design and maintenance practices and their impacts on Illinois roadway safety. An integrated modeling framework that includes modules for (1) geometric design simulation, (2) operating speed‐profile prediction, and (3) crash rate prediction, is proposed. Based on this research, a benefit–cost analysis was also developed to quantify the economic benefits of various strategies for roadway safety improvement. All models were programmed into an Excel VBA‐based computer tool to facilitate decision making. The outcome of this project may be suitable for implementation in a wide range of application contexts.
Geopolimer beton specifikáció: általános előírás
Specification of Geopolymer Concrete: General Guide
Szerző(k):
A. Shayan
Austroads Australia
Terjedelem: 22 oldal
This general guide contains: an introduction to geopolymer concrete, its constituents and how it is manufactured,, an examination of how geopolymer binder differs from Portland cement, the status of geopolymer concrete as a construction material. It also includes a brief summary of Austroads project TS1835, initiated to develop member agencies’ practical knowledge in geopolymer concrete, which includes: the conclusions drawn from an extensive literature review, identifying important parameters related to manufacture and performance of geopolymer concrete, as well as gaps that existed in knowledge at the start of this project, and the conclusions of the experimental work conducted under this project. Finally, the guide compares the differences and similarities between the specification of geopolymer concrete and concrete made with Portland cement.
Mintanagyság következtetések többnapos GPS háztartási utazásfelvételeknél
Sample Size Implications of Multi-Day GPS-Enabled Household Travel Surveys
Szerző(k):
L. Rizzo, G.D. Erhardt
Transportation Research Board USA
Terjedelem: 34 oldal
There has long been interest in conducting travel surveys in which the same respondent provides information for multiple travel days, but such surveys have been limited by the challenge of ameliorating biases resulting from survey fatigue. More recently, new technology (in the form of GPS-enabled travel surveys) has made multi-day data collection more practical by offering the promise of a lower respondent burden. Despite this progress, questions remain about the value of additional days of survey data versus the value of additional respondents. NCHRP Project 08-36/Task 123 seeks to address these questions by evaluating whether or not GPS-enabled multiday surveys overcome the survey fatigue challenges faced with multi-day diary surveys, investigating the effects of using multi-day data for developing travel demand models, and providing empirical evidence on the sample size implications of multi-day versus single-day surveys.
Útburkolat textúra mérés és értékelés nemzetközi tapasztalatai és távlatai. Workshop összefoglaló
International Experience and Perspective of Pavement Texture Measurements and Evaluation – Synopsis of a Workshop
Szerző(k):
B.L. Schleppi, M.Y. Mikhail, G.K. Chang
Transportation Research Board USA
Terjedelem: 106 oldal
This Transportation Research E-Circular includes a synopsis of presentations at the workshop “International Experience and Perspective of Pavement Texture Measurements and Evaluation” held at the 94th Annual Meeting of the Transportation Research Board (2015). This workshop was sponsored by the Standing Committees on Pavement Surface Properties and Vehicle Interaction, Pavement Structural Modeling and Evaluation, Characteristics of Asphalt–Aggregate Combinations to Meet Surface Requirements, and Transportation-Related Noise and Vibration. Presentations were:
Fundamentals of Pavement Texture Measurement and Interpretation, UK’s Experiences on Pavement Texture Measurement and Interpretation, US’ Experiences on Pavement Texture Measurement and Interpretation, New and Improved ISO Standards for Texture Measurements, EU project ROSANNE — ROlling resistance, Skid resistance, ANd Noise Emission, Measurement Standards for Road Surfaces and finally Q&As and Panel Discussion on Pavement Texture Measurement and Interpretation
Teljesítmény alapú közúti vonalvezetés tervezési folyamat
A Performance-Based Highway Geometric Design Process
Szerző(k):
T.R. Neuman, R.C. Coakley, S. Panguluri, D.W. Harwood
Transportation Research Board USA
Terjedelem: 266 oldal
NCHRP Research Report 839: A Performance-Based Highway Geometric Design Process presents a new process for highway geometric design that is more aligned with current expectations of transportation agencies and their communities and makes full use of the tools available to them. The report reviews the evolution of highway design, presents several key principles for today’s design challenges, recommends a new highway geometric design process, and demonstrates the value of the process through six illustrative case studies. The new process focuses on the transportation performance of the design rather than the selection of values from tables of dimensions applied across the range of facility types.
Csomópontok biztonsága és hatékonysága
Safety and efficiency at intersections
Szerző(k):
T. Brown, S. Griffith
Resolve Group, New Zealand
Terjedelem: 93 oldal
This report considers evidence on safety and efficiency at intersections, using New Zealand data and international research, and outlines a systematic approach for evaluating the safety and efficiency benefits at intersections, as part of the project development process. A review of New Zealand and international practices, analysis tools, guides and processes were considered. The authors found very little in the literature to define what is considered to be an acceptable trade-off between safety and efficiency at intersections, largely due to the existing separation of the two fields in all jurisdictions researched. A recommended solution has been presented in the form of a ‘proof of concept’ evaluation framework, which takes into account a range of factors and case studies. It is recommended that the transport sector considers utilising this framework as a decision support tool in ensuring the correct decisions, with respect to delivering against safety and efficiency outcomes, are made at the appropriate stage of the project development.
Torlódás és megbízhatóság áttekintése: összefoglalás
Congestion and Reliability Review: Summary
Szerző(k):
Deloitte Touche Tohmatsu Limited Australia
Terjedelem: 44 oldal
This summary provides an overview of the Congestion and Reliability Review which measures levels and identifies key causes of congestion across major cities in Australia and New Zealand. The Review proposes an approach to identifying and assessing congestion interventions and overlays the key areas of focus for road and transport agency capability development in order to assist agencies in developing a congestion mitigation roadmap.
Torlódás és megbízhatóság áttekintése: teljes jelentés
Congestion and Reliability Review: Full Report
Szerző(k):
Deloitte Touche Tohmatsu Limited Australia
Terjedelem: 256 oldal
The Congestion and Reliability Review measures the levels of congestion across major cities in Australia and New Zealand and identifies the key causes of congestion. The report proposes an approach to identifying and assessing congestion interventions and overlays the key areas of focus for road and transport agency capability development to assist agencies in developing a congestion mitigation roadmap.
Intelligens közlekedési rendszer vagyonelemek megbízhatóság központú fenntartási stratégiája és keretrendszere
Reliability-centred Maintenance Strategy and Framework for Management of Intelligent Transport System Assets
Szerző(k):
I. Espada, L. Inglis
Austroads Australia
Terjedelem: 65 oldal
This report provides a reliability-centred maintenance (RCM) strategy and framework to manage intelligent transport system (ITS) assets. ITS assets play a key role optimising efficiency and minimising crash risk in modern road network operations. ITS devices, however, fail frequently and every time they fail, the device can either be unavailable or operating in a degraded state for a long time. Unscheduled maintenance is costly and faults can potentially occur during critical times when the ITS asset is required to be functioning as designed/intended causing avoidable congestion cost and an increase in the risk of an incident. RCM is the application of engineering principles to manage the consequences of failure under a constrained maintenance budget. The use of RCM was raised in Austroads project AT1534 in 2013 as a potential approach to dealing with the issue of ITS failures under constrained maintenance budgets. The report covers the identification of key success factors, confirmation of the benefits and acceptability of RCM within jurisdictions including their contractors and suppliers, design of an RCM process template, and drafting of a road map for moving from the current practice to RCM.