Studies to determine the effectiveness of longitudinal channelizing devices in work zones.

PDFTech ReportFHWA/TX-11/0-6103-1Project 0-6103Work zone traffic controlHighway traffic control systemsTraffic assignmentTexasUnited States. Federal Highway AdministrationFinley, Melisa D. (Melisa Dayle)Theiss, LuAnnTrout, Nada D.Miles, Jeffrey D.Nelson, Alicia A.Texas Transportation InstituteTexas. Dept. of Transportation. Research and Technology Implementation OfficeUnited States. Federal Highway AdministrationUS Transportation CollectionThis report describes the methodology and results of analyses performed to determine whether the following longitudinalchannelizing device (LCD) applications improve the traffic safety and operations of work zones relative to the use of standarddrums:\ue2\u20ac\ua2 Continuous LCDs in the vicinity of exit ramps on high-speed, limited-access facilities.\ue2\u20ac\ua2 Continuous LCDs in the merging taper of a lane closure on low-speed roadways.\ue2\u20ac\ua2 Single LCDs (similar to Type 3 barricades) in the merging taper of a lane closure on high-speed roadways.\ue2\u20ac\ua2 Continuous LCDs in the vicinity of driveways on low-speed urban roadways.Based on the research findings, researchers recommended the use of continuous LCDs in the immediate vicinity of an exitramp within a lane closure under the following conditions:\ue2\u20ac\ua2 When a high number of deliberate intrusions into the work zone are expected or occur while using standardchannelizing devices.\ue2\u20ac\ua2 In situations where the exit ramp opening (in feet) is less than or equal to two times the posted speed limit (in mph),workers and equipment are in the work area near the exit ramp opening, and there are concerns that drivers mayunintentionally enter the work area trying to access the exit ramp.Recommendations regarding the minimum exit ramp opening length within a work zone lane closure and the use of a closer drumspacing in the immediate vicinity of exit ramps are also discussed. Researchers do not recommend the use of continuous LCDs orsingle barricade style LCDs to form a lane closure merging taper. While continuous LCDs may also be used to delineate the edgeof a travel lane in a work zone on an urban roadway, the height and location of the LCDs should be considered since they impactthe ability of drivers to view approaching traffic. Researchers also discuss LCD delineation and other implementationconsiderations