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dc.contributor.authorEasa, Said M
dc.contributor.authorAli, Muhammad Z. A.
dc.contributor.authorDabbour, Essam
dc.date.accessioned2018-03-14T05:22:10Z
dc.date.available2018-03-14T05:22:10Z
dc.date.issued2005
dc.identifier.citationhttps://goo.gl/VZF5EJen_US
dc.identifier.urihttps://dspace.adu.ac.ae/handle/1/631
dc.descriptionEasa, S. M., Ali, M. Z., & Dabbour, E. (2005). Offsetting opposing left-turn lanes for intersections on horizontal curves. Journal of transportation engineering, 131(11), 835-842.en_US
dc.description.abstract: Left-turn vehicles need sufficient sight distance to decide when it is safe to turn left crossing the lane(s) used by the opposing traffic. Current AASHTO policy recommends that the adequacy of sight distance for left turns should be checked for the reason that the opposing left-turn vehicles can block a driver’s view of oncoming traffic. Previous studies developed guidelines for offsetting opposing left-turn lanes to overcome this problem. However, these guidelines are only applicable to intersections with no curvature. This paper presents a mathematical model for calculating the required minimum left-turn lane offset and the median width (to accommodate the offset), when the intersections are located on horizontal curves. The provision of required offset ensures that the left-turn vehicles have unobstructed required sight distance. An application of the model is presented for divided highways with median width of 4.88 m assuming general values of other variables. The model is translated into an Excel worksheet in which the calculations for the required minimum offset and median width can be performed for any geometric configuration (e.g., curvature of major road, number of lanes, median and lane widths of the minor and major roads, etc.). Other design factors may be also input based on field observations, including design speed along the major road and longitudinal and lateral positioning of vehiclesen_US
dc.language.isoen_USen_US
dc.publisherAmerican society of civil engineering (ASCE)en_US
dc.subjectLeft-turnsen_US
dc.subjectSight distancesen_US
dc.subjectHighway designen_US
dc.subjectRoadsen_US
dc.subjectIntersectionsen_US
dc.titleOffsetting Opposing Left-Turn Lanes for Intersections on Horizontal Curvesen_US
dc.typeArticleen_US
dc.identifier.doihttps://doi.org/10.1061/(ASCE)0733-947X(2005)131:11(835)


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