详情

Examine Trade-Offs between Center Separation and Shoulder Width Allotment for a Given Roadway Width

项目名称：	Examine Trade-Offs between Center Separation and Shoulder Width Allotment for a Given Roadway Width
摘要：	Studies have shown that four-lane undivided roadways have poor safety performance compared to four-lane divided and two-lane cross-sections. Four-lane undivided rural highways experience relatively high crash frequenciesâespecially as traffic volumes increaseâresulting in conflicts with high-speed opposite-direction vehicles. However, there is not always sufficient space within the available right-of-way to accommodate a traditional four-lane divided cross-section. Some states, including Texas, have started providing a narrow centerline buffer area that is separated by longitudinal pavement markings. This additional buffer area shifts the lateral placement of vehicles and introduces a greater physical separation between approaching vehicles. However, the provision of centerline buffer comes at a cost of reduced lane or shoulder widths. A better understanding of the benefits of center separation, lane and shoulder combinations would provide useful information to designers who make decisions on cross-sections for new and resurfaced roadway segments. he purpose of this project is to provide a practical framework that TxDOT can use to choose between cross-sectional design alternatives to optimize operational and safety performance on rural highways. This framework will incorporate variables such as traffic volume, heavy vehicle mix, speed, and access point density. Researchers will collect and analyze data for four-lane sites with centerline buffers and compare their safety and operational performances with traditional four-lane undivided sites. Additionally, this research will quantify the differences in the performance of four-lane undivided highways when compared to other cross-sectional designs. Researchers will use observed data and simulation to achieve the project objectives.
状态：	Completed
资金：	$32,775
资助组织：	Federal Highway Administration<==>Texas Department of Transportation
项目负责人：	Schwerdt, Tom
执行机构：	Texas A&M Transportation Institute (TTI)
开始时间：	20190719
预计完成日期：	20210831
主题领域：	Design；Highways