Utilizing Automated Data Collection Vehicles in Determining the Fore Slopes of Shoulders: FHWA-WY-10/06F
The Wyoming DOT has an interest in collecting automated data on pavement shoulders. Such data would include shoulder width, type, as well as slope. Pathway Services Inc. has been collecting Pavement Management Systems (PMS) data on roadways in Wyoming, and indicated they had the ability to measure the transverse profile of 10 to 20 feet from the white strip shoulder marking. Pathway Services has offered to provide measurements on test sections in Wyoming since they had not collected such data for any other states, so it was important to them to determine the limitations or potential of the system. The test sections included seventy miles of Wyoming highways with shoulder widths varying from zero to ten feet in two foot increments.
Vegetation observations were made by researchers from the Wyoming T2-LTAP Center on the same day when Pathway’s data was collected to ensure identical conditions. It was found that the section with no shoulder had the most vegetation and the most varied slope measurements. It was concluded that vegetation does affect the accuracy of the sensor and that the sensor could not read past the pavement taper. In addition, the manually
collected slope measurements and the automated slope measurements were statistically different on most of the sections included in the experiment.