Nemzetközi szemle: December
Aszfalt burkolatok életciklus költség meghatározásának legjobb gyakorlata
Best Practices for Determining Life Cycle Costs of Asphalt Pavements
Szerző(k): Gu, N. Tran
National Center for Asphalt Technology USA
Terjedelem: 35 oldal
State highway agencies (SHAs) continually face important financial decisions when planning a new or reconstructed highway. For example, what is the initial investment for the highway? How much is needed periodically to maintain the highway in good pavement condition? What materials should be used to build the pavement? The answers to these questions may require a life cycle cost analysis (LCCA) based on the time value of money concept to assist in the final decision. To help SHAs and other agencies conduct such an analysis, this report provides best practices for properly determining inputs for use in their LCCA procedures and calculating the life cycle costs of pavement alternatives. The report is of immediate interest to engineers in SHAs, consulting firms, and the paving industry with responsibility for conducting LCCA as part of the pavement type selection process.
Az adatvezérelt közlekedésbiztonság új irányzatai
New Directions for Data-Driven Transport Safety
Szerző(k): The International Transport Forum, OECD
Terjedelem: 82 oldal
This report explores how seamless data collection, analysis and sharing can unlock innovations in transport safety. The rise of smartphones, sensors and connected objects is relentlessly producing more data. Progress in computing power, data science and artificial intelligence make it possible to interpret them. This presents an opportunity for the transport sector in general and for transport safety in particular. This report thus focuses on road safety, drawing on experiences from all transport modes. It examines emerging solutions to better assess crash numbers and to understand factors that contribute to them. It also identifies ways to address infrastructure safety problems in a proactive manner and to tackle road user errors. Finally, the report explores how road safety can benefit from driver assistance systems and cooperative connected solutions. The focus here is on the role of data sharing, including such important aspects as privacy protection, data standards and the role of partnerships. The work builds on the findings of a workshop held in December 2018 and on input from numerous experts.
Az időbeli és térbeli útdíjazás társadalmi és elosztási hatásai
Social and distributional impacts of time and space-based road pricing
Szerző(k): Nunns, E. Whitaker, S. Donovan
MRCagney Pty Ltd, New Zealand
Terjedelem: 113 oldal
This report outlines a general framework that can be used to analyse the social and distributional impacts of road pricing in the New Zealand context and applies it to two hypothetical case studies of road pricing schemes in New Zealand cities. This framework attempts to bring together multiple dimensions of social and distributional impacts in a relatively accessible way to describe relevant impacts on households and individuals and communicate them to policy-makers and the public in a way that can inform the design of pricing schemes and mitigation measures.
Az aszfaltvastagság hatása a burkolat minőségére
Impact of Asphalt Thickness on Pavement Quality
Szerző(k): R.S. McDaniel
Purdue University, USA
Terjedelem: 131 oldal
The ratio of the lift thickness to nominal maximum aggregate size (NMAS) is critical to achieving adequate asphalt mixture compaction during construction, which in turn has a profound impact on asphalt pavement performance and durability. If the lift thickness is inadequate, there is not enough room for the aggregate particles to be reoriented and densified; this can be exacerbated by rapid cooling of thin lifts, which shortens the time available for compaction. If the lift is too thick, the material at the bottom of the lift may be beyond the zone of influence of the compactor and thus may not be adequately densified. This synthesis was conducted to summarize the state of the practice regarding the effects of lift thickness on ultimate pavement performance.
Az alkalmazkodó jelzőlámpás forgalomirányítási technológia értékelése
Evaluation of Adaptive Signal Control Technology
Szerző(k): R.F. Benekohal, H. Jeon, J.J. Osorio, B. Garshasebi
University of Illinois at Urbana–Champaign, USA
Terjedelem: 61 oldal
This report presents the results of field evaluation of an adaptive signal‐control technology (ASCT) system—SynchroGreen—deployed on the Neil Street corridor in Champaign, Illinois. The Illinois Department of Transportation (IDOT) was interested in field evaluation of an ASCT on a corridor, in terms of traffic safety and operational efficiency. SynchroGreen was selected for field implementation on six intersections along Neil Street. This report is the sixth of the ASCT study, and it provides a brief summary of the other studies and new findings regarding the ASCT performance during heavy traffic from the minor street and heavy traffic due to special events. For the “first year” evaluation, data from 2015 was used; and for the “final year” evaluation, data from 2017 was used. Unlike the outcome of the “first year” evaluation, the “final year” evaluation showed improvements on the performance indicator (PI) in only 5% of the lane groups (cases), no change in 32%, and deterioration in 63%. The system was unable to respond properly to volume increases on the minor street (Kirby Avenue), due to either peak‐hour demand or special event traffic, and failed to allocate the unused green time on the major street to the minor street that had cycle failures. Multiple‐vehicle fatal and injury (FI) crashes had a crash‐modification factor (CMF) of 0.67, which was not significant at the 95% confidence level but clearly indicated a decreasing trend due to implementation of the ASCT system. Decreasing trends in the angle and rear‐end crashes, as well as Type A and Type C injuries, were observed; but they were not statistically significant. The travel times were increased in the preferred directions, which was not a desirable outcome. Several recommendations were made to vendors to provide a more desirable ASCT system.
Automatikus útburkolat állapot felvételek
Automated Pavement Condition Surveys
Szerző(k): L.M. Pierce, N.D. Weitzel
Terjedelem: 124 oldal
Pavement condition data is a critical component for pavement management systems in state departments of transportation (DOTs). The data is used to establish budget needs, support asset management, select projects for maintenance and preservation, and more. Data collection technology has advanced rapidly over the last decade and many DOTs now use automated data collection systems. This synthesis documents agency practices, challenges, and successes in conducting automated pavement condition surveys. Information used in this study was gathered through a literature review, a survey of state departments of transportation and Canadian provincial transportation agencies, and follow-up interviews with selected agencies. Three case examples provide additional information on agency practices for conducting automated pavement surveys. This synthesis is an immediately useful document that records the practices that were acceptable with the limitations of the knowledge available at the time of its preparation.
Életciklus értékelési eszköz fejlesztése rugalmas és merev útburkolatok megőrzéséhez és fenntartásához I és II kötet
Development of a Life-cycle Assessment Tool for Pavement Preservation and Maintenance on Flexible and Rigid Pavement Volume I + II
Szerző(k): Zhou, E. Okte, S. Sen, H. Ozer, I.L. Al-Qadi, J.R. Roesler, K. Chatti, S. Rajaei
University of Illinois at Urbana-Champaign, Michigan State University, USA
Terjedelem: 101 + 32 oldal
A complete LCA methodology was developed to quantify sustainability impacts of preservation activities for asphalt and concrete surfaced pavements. The LCA models and methodology was implemented in a software tool to support making project-level decisions in between various preservation and rehabilitation activities. The key components of the development include the inventory analysis used in the LCA calculations, treatment lifetime models and decision trees for preservation treatment selection. A nationwide survey was conducted through questionnaires. Questionnaires were designed specifically to target collecting data to build lifetime models in addition to agency experiences and practices. Decision trees were developed to guide decision makers to select from various preservation and rehabilitation options for a given existing pavement condition and traffic information. Data for the LCA also included that available in the literature or other publicly and commercially available databases to determine the LCA impacts of different preservation and maintenance schedules. The LCA scope includes materials, construction, maintenance and rehabilitation, and use stages. The inventory analysis was performed on data applicable to all regions in the United States. Volume II details the background and explanation of models applied in the use stage and work zone of life cycle assessment (LCA) on pavement preservation and maintenance schedules.
A mobilitás mint szolgáltatás (MaaS) lehetőségei
Opportunities in Mobility as a Service (MaaS)
(a letöltés ingyenes regisztrációval lehetséges)
Terjedelem: 90 oldal
Mobility as a Service, referred to as ‘MaaS’, represents the opportunity for all available public and private transport services to be integrated and bundled into a platform directly accessible by the individual travellers through their mobile devices, enabling door-to-door journey, with clear options on travel time, transport modes, and price, and centralising journey information, journey planning, service reservation, and payment. This concept is challenging the traditional transport landscape with potential new players set to take a key customer-facing role going forward as MaaS operators, and existing roles and business models required to adapt. The development of MaaS in Australia and New Zealand will likely be shaped by market opportunities. However, it will require strong public-sector leadership to develop integrated mobility strategy, understand and support the new business models MaaS implies, and assess and manage the impacts on existing services and legislation, including existing and planned public transport infrastructure and services.
AZ USA Szövetségi Útügyi Hatósága bemutató projektje az aszfalt burkolatok tartósságának megnövelt helyszíni burkolatsűrűséggel történő javítására 2. fázis
FHWA Demonstration Project for Enhanced Durability of Asphalt Pavements through Increased In-place Pavement Density, Phase 2
Szerző(k): Aschenbrener, F. Leiva, N. Tran
National Center for Asphalt Technology at Auburn University, USA
Terjedelem: 80 oldal
Based on prior studies, a 1 percent increase to in-place asphalt pavement density achieved through improved compaction was estimated to improve the fatigue performance of asphalt pavements between 8 and 44 percent and improve rutting resistance by 7 to 66 percent. A 1 percent increase in in-place density was estimated to extend the service life by 10 percent, conservatively. Recognizing the importance of in-place density in building cost effective asphalt pavements, a Federal Highway Administration (FHWA) Demonstration Project was initiated for Enhanced Durability of Asphalt Pavements through Increased In-place Pavement Density. The objective of this Demonstration Project was to determine the benefit of additional compaction and show that additional density could be obtained through improved techniques. Many States also added additional compaction equipment and evaluated other methods that could help obtain additional in-place density. Phase 2 of this Demonstration Project included two major components: (1) a literature review to identify how much in-place density is enough and (2) the construction of field demonstration projects in eight States. The literature review identified best practices for sufficient in-place density for long-life asphalt pavements and provided examples of specifications from the State highway agencies (SHAs) that have successfully achieved the sufficient in-place density for asphalt pavements.
3 dimenziós lézer szkenner prototípus fejlesztése útburkolat megőrzési alkalmazásokhoz
Development of a Three-Dimensional Laser Scanning Prototype for Pavement Preservation Applications
Szerző(k): Kouchaki, H. Roshani, Y.G. El Hachem, J.B. Hernandez, J.A. Prozzi
The University of Texas at Austin
Terjedelem: 103 oldal
The connection between the pavement friction and surface macro- and micro-texture makes pavement texture a vital topic for highway agencies and state Departments of Transportation to address. Accordingly, measuring surface texture is of prime importance in pavement preservation applications. Currently, most highway agencies rely on subjective measuring methods of pavement texture that are not reliable. With the recent advancements in laser technologies, highway agencies are gearing towards employing such developments that could potentially contribute towards better pavement surface texture characterization. With better surface texture characterization, they can better assess, monitor, and improve the pavement texture to provide better skid resistance for their highway network with the aim of ensuring safer roads for the public. This report proposes a laser scanning prototype for the characterization of the micro- and macro-texture of road surfaces. This prototype system has the advantage of capturing 3D data on pavement surfaces using an automatic, simple, and quick operation. This prototype is able to work in laboratory and in field. The development stages of this prototype are provided in this report. In addition, this report discusses different applications of the prototype created.