Cape May County Airport

Pavement Testing at Cape May County Airport (Click to Zoom)

The Cape May County Airport (designation WWD) in Rio Grande, NJ is a fully in-service airport that includes the FAA Research Taxiway. Known as Taxiway C, this pavement section opened in 2017 with a full array of lights and six pavement test strips, and is designated towards investigations into pavement technologies and airport safety. The Research Taxiway allows for the design, testing, evaluation, monitoring, and reporting of full-scale projects in a real-world environment.

Cape May County Airport (WWD) Layout with Research Taxiway C (Click to Zoom)

One such pavement test performed using the Research Taxiway was an exploration of various surface profiling devices. These devices record and analyze pavement roughness, which is very important for the high ground speeds that aircraft reach. Excessively rough pavement can interfere with the pilot’s ability to control the aircraft and negatively impact passenger comfort. To prevent this, it is important that equipment is able to quantitatively measure pavement roughness, and can do so accurately compared to other devices. The goals of this research project were as follows:

• to examine the accuracy of various profiling devices compared with each other and to surveying data
• to examine the profile smoothness/roughness and survey elevation measurements
• to recommend devices for profiling/surveying and provide procedures for the devices

The profiling devices used in the project were the Inertial Profiler, Walk-Behind Surface Profiler, Walking Road Profiler, California Profilograph, and 12-foot Straightedge, as well as a rod & level for surveying of the site. To ensure consistency, the taxiway was marked for five longitudinal runs based on the centerline and fourteen transverse runs at even intervals. The distance between runs was the minimum amount required as detailed in FAA standards, known as Advisory Circulars (ACs). Testing was done for the surface profile, straightedge, and profilograph index (PI) measurements. Profile measurements were compared to survey data taken with a rod & level and between the devices. Straightedge and PI measurements were compared to roughness requirements detailed in the FAA ACs as well as between the devices.

The computer program ProFAA was used in this project to enable a straightforward comparison of the devices. ProFAA is a software published by the FAA that is used for viewing and analyzing surface profiles. The analysis includes calculation of roughness indexes, simulation of devices such as a straightedge or profilograph and the associated results, and simulation of aircraft acceleration response on the profile. After ProFAA analysis, the test results between all devices could be compared.

Testing with the five devices was done in August 2017, just after repaving of the taxiway. The straightedge, walk-behind profiler, inertial profiler, and profilograph results were compared to FAA straightedge requirements. The straightedge’s results were taken directly, while the other devices recorded a surface profile and used ProFAA’s straightedge simulation to obtain results. The profilograph, walk-behind profiler, and inertial profiler results were compared to FAA PI requirements. The profilograph’s results were taken directly, while the other devices again used ProFAA to perform a profilograph simulation on the recorded profiles. Lastly, the profilograph, inertial profiler, walk-behind surface profiler, and walking profiler results were compared to the survey data taken with a rod & level. This testing and analysis completely addressed all objectives.

For more information on the profiling devices and software mentioned on this page, follow the links to the detailed FAA webpages.

Inertial Profiler

Walk-Behind Surface Profiler

Walking Road Profiler

California Profilograph

Straightedge

ProFAA

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