• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.324-327
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• 2011

The design requirement for ground mounted sign structures are fairly well defined in the AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaries, and Traffic Signals and consists of applying an equivalent pseudo-dynamic loading to account for the dynamic effects of wind loads and ignores the dynamic effect due to moving vehicle loads. This design approach, however, should not be applied to the design of bridge mounted sign structures because ignoring the dynamic effects of the moving vehicle loads may produce non-conservative results, since the stiffness of the bridge structure can greatly influence the behavior. Not enough information is available in the literatures which provide guide lines to include the influence of moving vehicles in the design of the bridge mounted sign structures. This paper describes a theoretical methodology, Bridge-Vehicle Interaction Element, which can be utilized to account for the dynamic effect of moving vehicles. A case study is also included where this methodology was successfully applied. It was concluded that the bridge-vehicle interaction finite element developed can provide a more accurate representation of the behavior of bridge mounted sign structures. The result of these analysis enabled development of simple and effective retrofitting scheme for the existing support system of bridge-mounted-structure.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.101-112
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• 2009

Recently, with the existing speed-management by law enforcements and physical speed-reduction facilities, the country newly adopted Driver Feedback Sign (DFS) system, which displays driving speed in order to guide the driver to an advisable driving condition. DFS is mainly used in school zones due to reasons related to the ITS. Accordingly, because it is predictable that DFS will result in speed-reduction without legal forces and would have an effect on physical speed-reduction facilities, intersection, crosswalks, and road-alignments, this study will try to verify the efficiency of DFS by researching the vehicle speed in national highways and school zones, which have similar conditions to the urban arterial road. In consequence, on national highways, the drivers had a tendency to travel according to the road-environment such as urban arterial road and not reduce speed voluntarily. In school zones, drivers tend to reduce speed in mornings and afternoons when children travel to school or home, showing that the resulting effect is different according to the road-environment where DFS is installed, and the time slot of the DFS.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.3
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• pp.91-98
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• 2011

Road signs are part of the traffic facilities intended to guide drivers to their destinations in a safe and comfortable manner. Due to the creation of new routes, changes to the old routes, and the deterioration of road signs, road signs do require efforts to do ongoing field investigations and put the results in a database. The purpose of this study was to propose methodologies to do field investigations and build a database for road signs efficiently. For that purpose, a mobile mapping system was designed for field investigations. The designed mobile mapping system was comprised of three cameras to produce image information about road signs, GPS/IMU/DMI to obtain information about the position and attitude of a vehicle, and a laser scanner to generate information about the locations of road signs and routes. Also proposed in the study was a procedure to automatically detect the areas of road signs in the road signs images and recognize their characters.