Sector : Engineering / Speed Calming Using Vertical Deflections in Road Alignment

Volume 1 , Issue 1
Hassan A. H. Mahdy
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Received : 12-06-2014
Published : 12-06-2014
Abstract
In densely urbanized areas with intensive land uses, traffic calming is a vital safety countermeasure to avoid violation of permitted speed-limits in hazardous areas such as; approaches of un-signalized at-grade intersections and upstream of surface pedestrian-crossings at or nearby densely land-uses such as; schools, hospitals, worship houses, etc. Previous researches showed that speed calming is usually done by either horizontal or vertical deflections in road alignments. Horizontal deflections in road alignment could be achieved through narrowing carriageway width, adopting horizontal alignment to prevent over speed, etc. while vertical deflections in road alignment could be achieved through instillation of speed humps upstream to the required speed calming or temporary work-zones locations. This paper focuses on determining actual traffic performance up- and down-streams of speed calming countermeasures using vertical deflections in road alignment (humps and speed tables) to study the influence of their physical and geometric characteristics on traffic performance, in terms of speed profile and traffic flow, and also to extract some guidelines for their most suitable locations.
Keywords
Road alignment, traffic in Urban areas, speed calming, traffic flow, speed humps.