Nemzetközi szemle: Február
Automatizált burkolat állapot mérések
Automated Pavement Condition Surveys
Szerző(k): L.M. Pierce, N.D. Weitzel
Transportation Research Board USA
Terjedelem: 123 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.
Gyalogos és kerékpáros számlálás ITS támogatással: egy állami multimodális számlálási program fejlesztése
ITS Support for Pedestrians and Bicyclists Count: Developing a Statewide Multimodal Count Program
Szerző(k): Codjoe, Y. Holamoge, R. Tian, C. Ash, W. Saunders
Louisiana Transportation Research Center USA
Terjedelem: 101 oldal
It is critical to understand the travel behavior of pedestrians and cyclists on Louisiana’s roadways. Not only do pedestrian and cyclist counts assist in research for safety, but these statistics are also essential for planners and policymakers when evaluating the usage of roadways and dictating infrastructure spending. Better understanding of overall statewide and location-specific transportation trends ultimately affects long-term planning and investment. Counting of pedestrians and cyclists using video surveillance and image processing technology has promised to be effective and feasible. While the research on newer technologies is not as robust as that of traditional ones, there is enough evidence to justify and guide the use of automated video count technology. This study concentrates on a specific algorithm, which would aid in automatic counting. This goal is achieved by following a part-based method, which utilizes the Histogram of Oriented Gradient (HOG) technique as well as a latent support vector machine (SVM). This technique was the preferred algorithm for automation due to its high-speed processing capability and its open source availability. The accuracy of the HOG algorithm in this study is validated using manual counts of pedestrians and cyclists from the collected video data. It is anticipated that the results will assist LTRC-16-4SA in evaluating available count technology options and in identifying preferred alternatives suitable for statewide deployment. The tested algorithm led to accuracy rates between 29-91% for pedestrians and 0-60% for cyclists. Despite the poor results obtained, the algorithm’s efficacy was thoroughly evaluated and documented. Some of the specific challenges faced in this study involved maintaining accurate viewpoint angles as well as conducting object detection in high-density environments and complicated scenes like intersections. New automated video counting systems have sought to improve algorithms in these problematic areas. Future work involves effectively handling these challenges and reevaluating the algorithm while considering others currently being used today.
Az átalakuló technológiák hatása a területfelhasználásra és a közlekedésre
Foreseeing the Impact of Transformational Technologies on Land Use and Transportation
Szerző(k): Kittelson & Associates, Bluemac Analytics, Irwin Writing/Editing
Transportation Research Board USA
Terjedelem: 188 oldal
The objective of this research is to develop a guidebook providing a template or procedure for practical assessment by DOT and other transportation-system decision-makers of the likely impact of transformational technologies on future activity centers, land use, and travel demand, with examples illustrating application of the template to address issues encountered by these decisionmakers.
Burkolat behajlási adatok felhasználása a rehabilitációs beavatkozások tervezéséhez javított módszerekkel
Improved Methods of Using Pavement Deflection Data in the Design of Rehabilitation Treatments
Szerző(k): Bodin, N. Zhalehjoo, D. Garton
(hozzáférés ingyenes regisztrációval)
Terjedelem: 79 oldal
New methods of using pavement deflection data were developed in the context of pavement structural rehabilitation treatment design. The project focused on two main components. The first was to assess the potential use of traffic speed deflectometer (TSD) deflection for the design of pavement structural treatments. The second component included formalising the pavement layer moduli back-calculation algorithm for use in mechanistic-empirical pavement treatment design. Using two databases of paired falling weight deflectometer (FWD) and TSD, a regression analysis of the deflection bowls allowed the determination of a robust relationship between maximum deflections measured by the two devices. The regression analysis did not allow the development of a process to predict deflection bowls equivalent to FWD measured bowls from TSD measured data. However, the regression parameters obtained for maximum deflections formed the basis of a deflection standardisation factor for the TSD proposed for the empirical design method of granular overlay. The algorithm suitable for the determination of pavement layer moduli from pavement surface deflection is detailed and described in the report based on previously used back-calculation methods. The project further developed the algorithm by adding optional features for the subgrade layer moduli and the sublayering process for granular layers. The proposed algorithm was tested using deflection data from case studies. The benefits of the optional features were also demonstrated.
Miért időszerű a torlódási díj bevezetése
Why it’s time for congestion charging
Szerző(k): Terrill, G. Moran, J. Ha
Grattan Institute Australia
Terjedelem: 58 oldal
Excessive congestion is costly and wasteful. While no one wants to pay more to drive, neither do they want the ordeal of delays and unpredictability when they do travel. Fast and reliable transport of people and goods is essential if we are to reap the economic and social benefits of big vibrant cities. There’s no doubt that congestion is a concern for many motorists in Australia’s big cities. Each of us is concerned about all the traffic slowing us down, but there is no trigger for us to be concerned about our contribution to slowing everybody else down. A cordon charge for people entering the CBDs of Australia’s largest cities in the morning peak, and leaving in the afternoon peak, would have a substantial impact. Even a modest charge would mean about 40 per cent fewer cars entering the central area in the morning peak, and speed increases of about 1 per cent across the network. These speed increases are similar to those from building new freeways that cost billions of dollars – whereas congestion charging has no net financial cost to the taxpayer.
Visszanyert aszfalt megnövelt arányú használatának értékelése az aszfalt keverékekben
Assessing Increased Use of Reclaimed Asphalt Pavement in Asphalt Mixtures
Szerző(k): Nair, S.D. Diefenderfer, B.F. Bowers
Virginia Transportation Research Council USA
Terjedelem: 51 oldal
In 2007, the Virginia Department of Transportation (VDOT) introduced specifications to allow asphalt surface mixtures to have up to 30% reclaimed asphalt pavement (RAP) without a change in the virgin binder grade. Since 2007, increasing material costs and a growing awareness of the quantity of RAP available for use have sparked interest in allowing asphalt mixtures to have a higher percentage of RAP. By 2013, VDOT had begun to consider the feasibility of allowing the use of surface mixtures with up to 45% RAP, and several trial sections were constructed containing mixtures with 20%, 30%, 40%, and 45% RAP for evaluation. This report presents the initial construction and laboratory performance data and discusses the lessons learned from these trials. In general, mixtures containing up to 45% RAP can be designed, produced, and constructed if proper procedures are followed and attention to detail is paid during design, production, and construction. As expected, all high RAP mixtures (i.e., mixtures containing >30% RAP) showed excellent rutting resistance based on laboratory testing. Laboratory performance testing indicated that the cracking resistance of high RAP mixtures depends on mixture and binder stiffness. The early field performance (2 to 3 years) of high RAP mixtures showed excellent rutting resistance and low values for the international roughness index, indicating smooth pavement. No premature cracks were observed in the high RAP sections. However, continued monitoring of these field sections is required to evaluate the long-term field performance.
Közúti közlekedésbiztonsági éves jelentés 2019
Road Safety Annual Report 2019
Szerző(k): The International Transport Forum OECD
Terjedelem: 60 oldal
The 2019 edition of the Annual Report of the International Traffic Safety Data and Analysis Group (IRTAD) contains the most recent road safety data and up-to-date information for 41 countries.
Főútvonali megbízhatósági teljesítmény mutatókra ható tényezők vizsgálata
Understanding Factors Affecting Arterial Reliability Performance Metrics
Szerző(k): J.C. Anderson, R. Sirupa, S. Kothuri, A. Unnikrishnan
Portland State University USA
Terjedelem: 118 oldal
In recent years, the importance of travel time reliability has become equally important as average travel time. However, the majority focus of travel time research is average travel time or travel time reliability on freeways. In addition, the identification of specific factors (i.e., peak hours, nighttime hours, etc.) and their effects on average travel time and travel time variability are often unknown. The current study addresses these two issues through a travel time-based study on urban arterials. Using travel times collected via Bluetooth data, a series of analyses are conducted to understand factors affecting reliability metrics on urban arterials. Analyses include outlier detection, a detailed descriptive analysis of select corridors, median travel time analysis, assessment of travel time reliability metrics recommended by the Federal Highway Administration (FHWA), and a bivariate Tobit model. Results show that day of the week, time of day, and holidays have varying effects on average travel time, travel time reliability, and travel time variability. Results also show that evening peak hours have the greatest effects in regards to increasing travel time, nighttime hours have the greatest effects in regards to decreasing travel time, and directionality plays a vital role in all travel time-related metrics.