Nemzetközi szemle: December
Átalakuló technológiák a közlekedésben
Transformational Technologies in Transportation
A. Mohaddes, P. Sweatman
Terjedelem: 86 oldal
This technical memorandum provides the review and findings of state of the activities conducted by CAVita relative to the transformational technologies identified by TRB. Connected–automated vehicles (CAVs) are a potential national ground transportation solution with high market, consumer, and societal significance; the realization of CAVs full potential will require sustained cooperation among many stakeholders. Shared-use services is a generational service economy concept that has extreme disruptive power in transportation and has a natural affinity with CAVs. It has a very high market potential, consumer, and societal significance. Unmanned aerial systems (UASs) are a national operations and mobility solution with significant market and consumer potential; the realization of UASs’ full potential will require government action and consumer acceptance. Internet of Things (IoT) is a technological megatrend that will underpin many smart products and services. Cybersecurity is an essential, high-value process technology that underpins many fields of system operations and consumer services. Smart cities is a technological mega-trend that bundles related technologies including big data and IoT. NextGen is a new-generation national system for the control of aviation operations. It is led and operated by government and enables high market and societal value. The need for and wide use of the system is not at issue. 3-D printing is a highly disruptive technology in manufacturing, logistics, and transportation. It has extremely high market value and flow-on effects, including the enterprises of IP, research and standards. Big data is an information technology that enables other transformational technologies, and game-changing advances in multiple fields of operation (including transportation).
Földi lézerszkenner alapú hídszerkezet állapot értékelés
Terrestrial Laser Scanning-Based Bridge Structural Condition Assessment
Y. Turkan, S. Laflamme, L. Tan
Iowa State University USA
Terjedelem: 37 oldal
Objective, accurate, and fast assessment of a bridge’s structural condition is critical to the timely assessment of safety risks. Current practices for bridge condition assessment rely on visual observations and manual interpretation of reports and sketches prepared by inspectors in the field. Visual observation, manual reporting, and interpretation have several drawbacks, such as being labor intensive, subject to personal judgment and experience, and prone to error. Terrestrial laser scanners (TLS) are promising sensors for automatically identifying structural condition indicators, such as cracks, displacements, and deflected shapes, because they are able to provide high coverage and accuracy at long ranges. However, limited research has been conducted on employing laser scanners to detect cracks for bridge condition assessment, and the research has mainly focused on manual detection and measurement of cracks, displacements, or shape deflections from the laser scan point clouds. This research project proposed to measure the performance of TLS for the automatic detection of cracks for bridge structural condition assessment. Laser scanning is an advanced imaging technology that is used to rapidly measure the three-dimensional (3D) coordinates of densely scanned points within a scene. The data gathered by a laser scanner are provided in the form of point clouds, with color and intensity data often associated with each point within the cloud. Point cloud data can be analyzed using computer vision algorithms to detect cracks for the condition assessment of reinforced concrete structures. In this research project, adaptive wavelet neural network (WNN) algorithms for detecting cracks from laser scan point clouds were developed based on the state-of-the-art condition assessment codes and standards. Using the proposed method for crack detection would enable automatic and remote assessment of a bridge’s condition. This would, in turn, result in reducing the costs associated with infrastructure management and improving the overall quality of our infrastructure by enhancing maintenance operations.
Az automatikus járművek fogyasztói elfogadása és hatása a közlekedési szokásokra
Consumer Acceptance and Travel Behavior Impacts of Automated Vehicles
J. Zmud, I. N. Sener, J. Wagner
Texas A&M Transportation Institute USA
Terjedelem: 32 oldal
This study provides a glimpse into the not-too-distant future by asking people in the general population how they would respond to the availability of self-driving vehicles, which might be on Texas roadways within a few years. Some elements of the technology are already available in vehicles today. Self-parking, adap¬tive cruise control, and automated braking are all available currently. In the near future, vehi¬cles might take over driving completely. The advent of self-driving vehicles could be truly transformative, but future acceptance and use are highly uncertain. People are in a wait-and-see position in terms of acceptance and use of self-driving vehicles.
Mikroszkopikus nagyméretű közlekedési adatok integrálása szimuláció alapú biztonsági elemzéshez
Integration of Microscopic Big Traffic Data in Simulation-Based Safety Analysis
Mohamed Abdel-Aty, Q. Shi, L. Wang, Y. Wu, E. Radwan, B. Zhang,
University of Central Florida USA
Terjedelem: 34 oldal
The advent of the Big Data era has transformed the outlook of numerous fields in science and engineering. The transportation arena expects to take advantage of Big Data through the popularization of Intelligent Transportation Systems (ITS). Judging by the data size, richness of information, and collection speed of data, ITS traffic detection systems serve as ideal sources of big traffic data. Collected from various sources, the data provide insight about the facilities at a microscopic level in real-time. Consequently, efficient integration and utilization of such data for better performance of transportation systems becomes a critical issue for traffic operators. In this project, different applications of the real-time microscopic traffic data were explored with a focus on operation efficiency and traffic safety. The applications range from direction measurement of operation efficiency and safety using the real-time traffic data to indirect use of the data in simulation tools. Overall, multiple tasks in this project demonstrated the great potential to apply microscopic traffic data to traffic safety studies and simulation applications.
Kis forgalmú burkolt utak felújításának újszerű tervezési módjai
Alternate Design Methods to Renew Lightly Traveled Paved Roads
Ch. Jahren, J. Yu, R.Ch. Williams
Iowa State University USA
Terjedelem: 71 oldal
Minnesota’s local highway agencies are tasked with maintaining their low-volume road networks with available financial resources, prompting increased interest in lower-cost pavement rehabilitation alternatives. In-place cold recycling technologies, such as cold in-place recycling (CIR) and full-depth reclamation (FDR), provide lower-cost opportunities to renew deteriorated roads than traditional rehabilitation methods, particularly if surfaced with a thin surface treatment such as a chip seal (seal coat) or microsurfacing rather than hot-mix asphalt. However, the resulting road surface may not meet some road users’ expectations. This study investigated the performance and economics of four pavement rehabilitation alternatives involving recycling technologies. The alternatives included CIR and FDR treatments with either an asphalt overlay or thin surface treatment. Fifteen case study sections in Minnesota and neighboring states were selected for performance evaluation and lifecycle cost analysis (LCCA). Pavement condition surveys were performed to evaluate the study sections’ pavement distresses and roughness. The results indicated satisfactory performance for fourteen sections, while a CIR section with a chip seal surface using quartzite as cover aggregate had extensive transverse cracking. The cause of the distress is not clear. The LCCA results indicate a 14% to 42% lower lifecycle cost for CIR and FDR treatments with chip seal surfaces. Costs savings may be achieved if asphalt overlay thicknesses are reduced, though chip seal surfaces may be rougher and nosier and require more maintenance than asphalt overlays. A decision tree was developed to aid local agencies during the treatment selection process.
Útpályaszerkezet teherbírás értékelése hálózati szinten
Pavement Structural Evaluation at the Network Level
Federal Highway Administration USA
Terjedelem: 12 oldal
The document is a technical summary of the Federal Highway Administration (FHWA) report, Pavement Structural Evaluation at the Network Level. It addresses the use of traffic speed deflection devices for the structural evaluation of pavements at the network level. Highlights from three major efforts—gathering information to identify viable devices, performing field trials at or near the Minnesota Department of Transportation MnROAD pavement test track facility near Maplewood, MN, to evaluate viable devices, and analyzing data to identify and select the best deflection indices—are presented. Suggestions for implementation of the results within network-level pavement management system (PMS) applications are also provided as well as recommended technology improvements.
A sebesség hatása a hidak dinamikus terhelési tényezőjére különböző belépési feltételeknél
Investigation of the Effect of Speed on the Dynamic Impact Factor for Bridges with Different Entrance Conditions
Y. Deng, B.M. Phares
Iowa State University USA
Terjedelem: 53 oldal
The dynamic interaction of vehicles and bridges results in live loads being induced into bridges that are greater than the vehicle’s static weight. To limit this dynamic effect, the Iowa Department of Transportation (DOT) currently requires that permitted trucks slow to five miles per hour and span the roadway centerline when crossing bridges. However, this practice has other negative consequences such as the potential for crashes, impracticality for bridges with high traffic volumes, and higher fuel consumption. The main objective of this work was to provide information and guidance on the allowable speeds for permitted vehicles and loads on bridges. A field test program was implemented on five bridges (i.e., two steel girder bridges, two pre-stressed concrete girder bridges, and one concrete slab bridge) to investigate the dynamic response of bridges due to vehicle loadings. The important factors taken into account during the field tests included vehicle speed, entrance conditions, vehicle characteristics (i.e., empty dump truck, full dump truck, and semi-truck), and bridge geometric characteristics (i.e., long span and short span). Three entrance conditions were used: As-is and also Level 1 and Level 2, which simulated rough entrance conditions with a fabricated ramp placed 10 feet from the joint between the bridge end and approach slab and directly next to the joint, respectively. The researchers analyzed and utilized the field data to derive the dynamic impact factors (DIFs) for all gauges installed on each bridge under the different loading scenarios.
A járműben kijelzett vezetési körülmény változási információ kockázat értékelése
Risk evaluation for in-vehicle sign information
E.J. Schlicht, N.L. Morris
University of Minnesota USA
Terjedelem: 48 oldal
The goal of the study was to examine the influence of in-vehicle signing (IVS) pertaining to four types of changing driving conditions and determine the utility and potential safety costs associated with the IVS information. Signage displayed on a personal navigation device was presented for specific zones within the simulation to assist drivers’ preparation for transitioning to new driving conditions ahead. These zones included: speed zone changes within the same roadway, notification of school zones, notification of work zones, and notification of curves. Driving performance measures known to be related to distraction as well as subjective usability and workload measures were used to help identify potential distraction associated with the IVS information. Moreover, risk analysis was conducted to evaluate the safety associated with IVS technology compared to the known safety levels with standard roadside signage. The objective measures collected in this study (both driving performance and risk analysis) indicated that implementing IVS technology would impact driving performance in the following manner: When IVS was deployed in the absence of external signs, speeding behavior significantly increased relative to baseline levels. IVS technology was not observed to impact speeding behavior when external signs were also present. Risk analysis suggested that IVS technology (when used in conjunction with external signs) can improve the safety associated with frontal-impact crashes; however, risk analysis proved that safety across all crash types was significantly reduced below baseline levels when IVS was used without external signs. Moreover, subjective usability results reinforced the driving performance findings.