The Experts below are selected from a list of 109815 Experts worldwide ranked by ideXlab platform
Stephen H Richards - One of the best experts on this subject based on the ideXlab platform.
-
driver behaviours on rural highways with and without Curbs a driving simulator based study
International Journal of Injury Control and Safety Promotion, 2014Co-Authors: Qiang Yang, Ryan Overton, Lee D Han, Xuedong Yan, Stephen H RichardsAbstract:The speed limit of 55 mph (88 km/h) is used typically on rural highways in the U.S. When Curbs are installed, a lower speed limit is suggested because running into Curbs at high speeds may cause significant vehicular damage and severe injuries. However, it has been argued that lowering the speed limit may cause confusion in drivers, who do not perceive the risk and tend to operate their vehicles at the same speed as before. To better understand driver behaviour on two-lane rural highways before and after curb installation, the authors conducted a series of experiments on a high-fidelity driving simulator in different posted speed limit, curb installation, lateral curb clearance, weather, visibility, and traffic conditions. Results of the study suggest that driver behaviours are influenced by the various factors in a complex and interrelated manner. It is likely that Curbs have no influence on a driver's selection of speed. Drivers do perceive the risk from the curb or the opposing traffic when selecting their lane positions. The available space between the curb and the opposing traffic is crucial and has significant effects on driving behaviours. The subjective effects of drivers are found to be influential to driving behaviours.
-
the influence of Curbs on driver behaviors in four lane rural highways a driving simulator based study
Accident Analysis & Prevention, 2013Co-Authors: Qiang Yang, Ryan Overton, Lee D Han, Xuedong Yan, Stephen H RichardsAbstract:The speed limit of 55mph (88km/h) is typically used on rural highways in the U.S. For locations where Curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45mph (72km/h) speed limit because, according to AASHTO, running into Curbs at high speeds may cause significant vehicular damage and even severe injuries. However, it has also been argued that lowering the speed limit after the installation of Curbs may cause confusion in drivers, who do not perceive the risk associated with the newly installed Curbs and tend to operate their vehicles at the same speed as before. To better understand driver behavior on rural highways before and after curb installation, and with different speed limits, researchers at the University of Tennessee conducted a series of experiments in two-lane and four-lane highways on a high-fidelity driving simulator. This paper mainly presents the findings from the four-lane study, and compares the results from the previous two-lane study. The scenario matrix consists of several dimensions including posted speed limit (45 and 55mph, or 72 and 88km/h), curb installation, lateral clearance between the edge of travel lane and the curb (2ft, 6ft, and no-curb, or 0.6m, 1.8m, and no-curb), weather (clear and fog), traffic conditions in the next lane (1400veh/h and 400veh/h), etc. For each subject under different experimental scenarios, detailed driving parameters, such as driving speed and vehicle position in the travel lane, were recorded and analyzed subsequently. Results of the study suggest that driver behaviors are influenced by the various factors in a complex and interrelated manner. It is likely that drivers do not perceive the risk from the curb in determining their speed on four-lane rural highways. However, it is found that Curbs may provide certain guidance to drivers, especially in selecting lane position. Compared to the previous research in two-lane conditions, it is found that drivers are more likely to choose driving speeds according to posted speed limits, rather than lane configurations. It is also found that the relative speed between driver's vehicle and ambient traffic or Curbs is an important factor determining drivers' perception of risk and thus their driving behavior. The influence of subjective effects of these factors to their driving behavior is also observed in the study. Language: en
-
influence of Curbs on traffic crash frequency on high speed roadways
Traffic Injury Prevention, 2011Co-Authors: Ximiao Jiang, Xuedong Yan, Baoshan Huang, Stephen H RichardsAbstract:Objective: Curbs are commonly used on roadways for drainage management, access control, and other positive functions. However, Curbs may also bring about unfavorable effects on drivers’ behavior and vehicle stability when hitting Curbs, especially for high-speed roadways. The objective of this article is to investigate whether the presence of Curbs along outside shoulders has produced adverse effects on traffic safety on high-speed roadways and whether increasing speed limits has created any further harmful effects. Methods: In this study, the Illinois Highway Safety Database from 2003 to 2007 was selected to evaluate the effects of Curbs over traffic safety on 2-lane and 4-lane non-freeways with speed limits of 45, 50, and 55 mph. Wilcoxon/Kruskal-Wallis nonparametric tests were conducted to compare the road-segment crash rates between 3 types of outside shoulders (curbed shoulder, soft flush shoulder, and hard flush shoulder) and 3 speed limits. In addition, the zero-inflated negative binomial models we...
-
driver behaviors on rural highways with and without Curbs driving simulator based study
Transportation Research Board 90th Annual MeetingTransportation Research Board, 2011Co-Authors: Qiang Yang, Ryan Overton, Lee D Han, Xuedong Yan, Stephen H RichardsAbstract:The speed limit of 55 mph (88 km/h) is typically used on rural highways in the U.S. For locations where Curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45 mph (72 km/h) speed limit because, according to AASHTO, running into Curbs at high speeds may cause significant vehicular damage and even severe injuries. However, it has also been argued that lowering the speed limit after the installation of Curbs may cause confusion in drivers, who do not perceive the risk associated with the newly installed Curbs and tend to operate their vehicles at the same speed as before. To better understand driver behavior on two-lane rural highways before and after curb installation and with different speed limits, researchers at the University of Tennessee conducted a series of experiments on a high-fidelity driving simulator. The scenario matrix consists of several dimensions including posted speed limit (45 and 55 mph, or 72 and 88 km/h), curb installation, lateral clearance between the edge of travel lane and the curb (2ft, 6 ft, and no-curb, or 0.6 m, 1.8 m, and no-curb), weather (clear and fog), visibility (day and night) conditions, traffic conditions in opposing lane (1400 veh/hr and 400 veh/hr), etc. For each subject under different experimental scenarios, detailed driving parameters, such as driving speed and vehicle position in the travel lane, were recorded and analyzed subsequently. Results of the study suggest that driver behaviors are influenced by the various factors in a complex and interrelated manner. It is likely that drivers do not perceive the risk from the curb or actually perceive more risk from the opposing traffic in determining their speed or lane position. In addition, the available space between the curb and the opposing traffic is crucial and has significant impact on driving behaviors.
Leonard G Luyt - One of the best experts on this subject based on the ideXlab platform.
-
the chimera that Curbs appetite
Journal of Medicinal Chemistry, 2018Co-Authors: Leonard G LuytAbstract:A chimeric drug design approach, merging the structure of an antagonist and an inverse agonist, results in a new molecular scaffold for targeting the ghrelin receptor (GHSR).
Wolfgang Förstner - One of the best experts on this subject based on the ideXlab platform.
-
a temporal filter approach for detection and reconstruction of Curbs and road surfaces based on conditional random fields
IEEE Intelligent Vehicles Symposium, 2011Co-Authors: Jan Siegemund, Uwe Franke, Wolfgang FörstnerAbstract:A temporal filter approach for real-time detection and reconstruction of Curbs and road surfaces from 3D point clouds is presented. Instead of local thresholding, as used in many other approaches, a 3D curb model is extracted from the point cloud. The 3D points are classified to different parts of the model (i.e. road and sidewalk) using a temporally integrated Conditional Random Field (CRF). The parameters of curb and road surface are then estimated from the respectively assigned points, providing a temporal connection via a Kalman filter.
-
Intelligent Vehicles Symposium - Curb reconstruction using Conditional Random Fields
2010 IEEE Intelligent Vehicles Symposium, 2010Co-Authors: Jan Siegemund, David Pfeiffer, Uwe Franke, Wolfgang FörstnerAbstract:This paper presents a generic framework for curb detection and reconstruction in the context of driver assistance systems. Based on a 3D point cloud, we estimate the parameters of a 3D curb model, incorporating also the curb adjacent surfaces, e.g. street and sidewalk. We apply an iterative two step approach. First, the measured 3D points, e.g., obtained from dense stereo vision, are assigned to the curb adjacent surfaces using loopy belief propagation on a Conditional Random Field. Based on this result, we reconstruct the surfaces and in particular the curb. Our system is not limited to straight-line Curbs, i.e. it is able to deal with Curbs of different curvature and varying height. The proposed algorithm runs in real-time on our demonstrator vehicle and is evaluated in urban real-world scenarios. It yields highly accurate results even for low Curbs up to 20m distance.
L.r. Costello - One of the best experts on this subject based on the ideXlab platform.
-
A review of tree root conflicts with sidewalks , Curbs , and roads.
Urban Ecosystems, 2003Co-Authors: T.b. Randrup, E.g. Mcpherson, L.r. CostelloAbstract:Literature relevant to tree root and urban infrastructure conflicts is reviewed. Although tree roots can conflict with many infrastructure elements, sidewalk and curb conflicts are the focus of this review. Construction protocols, urban soils, root growth, and causal factors (soil conditions, limited planting space, tree size, variation in root architecture, management practices, and construction materials) are discussed. Because costs related to sidewalk and curb damage are substantial, a review of research addressing repair, mitigation, prevention, and litigation costs is included. Finally, future research needs are discussed. Potential for conflicts between trees and sidewalks/Curbs is high when one or more of these factors are present: tree species that are large at maturity, fast growing trees, trees planted in restricted soil volumes, shallow top soil (hard-pan underneath top-soil), shallow foundations underneath the sidewalk (limited or no base materials), shallow irrigation, distances between the tree and sidewalk of less than 2.0–3.0 m., trees greater than 15 to 20 years old. The results of this survey indicate that cities are spending substantial sums of money to address conflicts between street tree roots and infrastructure. It can be inferred that most of these expenditures are spent dealing with problems that already exist. However, this raises the question: How much is being spent now to ensure that conflicts are minimized in the future? Future research should concentrate on plant factors, site design, and construction of sidewalks and Curbs. Also, more knowledge is needed about interactions between root growth and management techniques, such as pruning and irrigation. Finally, there is need for studies that will assist policy-makers to efficiently allocate funds among repair, mitigation, prevention, and legal remedies.
Qiang Yang - One of the best experts on this subject based on the ideXlab platform.
-
driver behaviours on rural highways with and without Curbs a driving simulator based study
International Journal of Injury Control and Safety Promotion, 2014Co-Authors: Qiang Yang, Ryan Overton, Lee D Han, Xuedong Yan, Stephen H RichardsAbstract:The speed limit of 55 mph (88 km/h) is used typically on rural highways in the U.S. When Curbs are installed, a lower speed limit is suggested because running into Curbs at high speeds may cause significant vehicular damage and severe injuries. However, it has been argued that lowering the speed limit may cause confusion in drivers, who do not perceive the risk and tend to operate their vehicles at the same speed as before. To better understand driver behaviour on two-lane rural highways before and after curb installation, the authors conducted a series of experiments on a high-fidelity driving simulator in different posted speed limit, curb installation, lateral curb clearance, weather, visibility, and traffic conditions. Results of the study suggest that driver behaviours are influenced by the various factors in a complex and interrelated manner. It is likely that Curbs have no influence on a driver's selection of speed. Drivers do perceive the risk from the curb or the opposing traffic when selecting their lane positions. The available space between the curb and the opposing traffic is crucial and has significant effects on driving behaviours. The subjective effects of drivers are found to be influential to driving behaviours.
-
the influence of Curbs on driver behaviors in four lane rural highways a driving simulator based study
Accident Analysis & Prevention, 2013Co-Authors: Qiang Yang, Ryan Overton, Lee D Han, Xuedong Yan, Stephen H RichardsAbstract:The speed limit of 55mph (88km/h) is typically used on rural highways in the U.S. For locations where Curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45mph (72km/h) speed limit because, according to AASHTO, running into Curbs at high speeds may cause significant vehicular damage and even severe injuries. However, it has also been argued that lowering the speed limit after the installation of Curbs may cause confusion in drivers, who do not perceive the risk associated with the newly installed Curbs and tend to operate their vehicles at the same speed as before. To better understand driver behavior on rural highways before and after curb installation, and with different speed limits, researchers at the University of Tennessee conducted a series of experiments in two-lane and four-lane highways on a high-fidelity driving simulator. This paper mainly presents the findings from the four-lane study, and compares the results from the previous two-lane study. The scenario matrix consists of several dimensions including posted speed limit (45 and 55mph, or 72 and 88km/h), curb installation, lateral clearance between the edge of travel lane and the curb (2ft, 6ft, and no-curb, or 0.6m, 1.8m, and no-curb), weather (clear and fog), traffic conditions in the next lane (1400veh/h and 400veh/h), etc. For each subject under different experimental scenarios, detailed driving parameters, such as driving speed and vehicle position in the travel lane, were recorded and analyzed subsequently. Results of the study suggest that driver behaviors are influenced by the various factors in a complex and interrelated manner. It is likely that drivers do not perceive the risk from the curb in determining their speed on four-lane rural highways. However, it is found that Curbs may provide certain guidance to drivers, especially in selecting lane position. Compared to the previous research in two-lane conditions, it is found that drivers are more likely to choose driving speeds according to posted speed limits, rather than lane configurations. It is also found that the relative speed between driver's vehicle and ambient traffic or Curbs is an important factor determining drivers' perception of risk and thus their driving behavior. The influence of subjective effects of these factors to their driving behavior is also observed in the study. Language: en
-
driver behaviors on rural highways with and without Curbs driving simulator based study
Transportation Research Board 90th Annual MeetingTransportation Research Board, 2011Co-Authors: Qiang Yang, Ryan Overton, Lee D Han, Xuedong Yan, Stephen H RichardsAbstract:The speed limit of 55 mph (88 km/h) is typically used on rural highways in the U.S. For locations where Curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45 mph (72 km/h) speed limit because, according to AASHTO, running into Curbs at high speeds may cause significant vehicular damage and even severe injuries. However, it has also been argued that lowering the speed limit after the installation of Curbs may cause confusion in drivers, who do not perceive the risk associated with the newly installed Curbs and tend to operate their vehicles at the same speed as before. To better understand driver behavior on two-lane rural highways before and after curb installation and with different speed limits, researchers at the University of Tennessee conducted a series of experiments on a high-fidelity driving simulator. The scenario matrix consists of several dimensions including posted speed limit (45 and 55 mph, or 72 and 88 km/h), curb installation, lateral clearance between the edge of travel lane and the curb (2ft, 6 ft, and no-curb, or 0.6 m, 1.8 m, and no-curb), weather (clear and fog), visibility (day and night) conditions, traffic conditions in opposing lane (1400 veh/hr and 400 veh/hr), etc. For each subject under different experimental scenarios, detailed driving parameters, such as driving speed and vehicle position in the travel lane, were recorded and analyzed subsequently. Results of the study suggest that driver behaviors are influenced by the various factors in a complex and interrelated manner. It is likely that drivers do not perceive the risk from the curb or actually perceive more risk from the opposing traffic in determining their speed or lane position. In addition, the available space between the curb and the opposing traffic is crucial and has significant impact on driving behaviors.
