Degree Granting Department
John Lu, Ph.D.
Larry Hagen, M.S.C.E.
Huaguo Zhou, Ph.D.
Crash rate, Crash data, Intersection approach, Operations, Crossroad
Signalized Intersections on the State Roads in Hillsborough and Pinellas County, Florida with observed left turn lane overflow (spill) were selected for a safety and operational study. The study analyzed the crash data for safety hazards that the situation presents. Crashes within 100 feet from the center line of the crossroad of intersections under study to distances 200 feet beyond the end of the turn lane were chosen for the analysis. Left turn overflow is the situation at the approach of an intersection where left turning vehicles back up from the turn lane into the through traffic lane.
Crashes within the intersection legs with the left turn lane overflow problems resulted in more crashes than the intersection legs without the spill problem at 95 percent confidence level. However the result was not overwhelming when 3 leg intersections are combined with 4 leg intersections. The rush periods within the leg of the intersection where left turn overflow occurred did not seem to have any correlation at all using paired t test.
Scholar Commons Citation
Sankah, Isaac Kwamena, "Safety Effects of Left Turn Overflow at Signalized Intersections" (2005). Graduate Theses and Dissertations.