Pavemetrics’ high-speed 3D laser pavement profiler (the LCMS) has officially passed NCAT’s rigorous longitudinal profiler certification program!

Through the joint efforts of Michael Baker International and Pavemetrics Systems Inc., Pavemetrics’ high-speed 3D laser pavement profiler (the LCMS) has officially passed NCAT’s rigorous longitudinal profiler certification program! Pavemetrics is proud to have worked with Michael Baker in order to reach this important industry milestone; receiving a pass validates the LCMS as an accurate and repeatable inertial profiler that is an acceptable alternative to older two-point profiler technology.

The LCMS is perhaps best known for its automated crack detection and measurement. Yet due to its high resolution scans (4,000 points across 4m) and the integration of Inertial Measurement Units, it can also be used to provide an incredibly precise longitudinal profile of the road. This is a key advantage for road data collection companies as they can now eliminate the associated cost and potential downtime as a result of adding a separate roughness measurement subsystem.

Compared to traditional two-point profilers, the LCMS 4m wide scan provides full lane coverage; pavement stripe to pavement stripe. Full lane width scans provide an advantage over traditional two-point profilers when it comes to compensating for driver wander. Through intensity data processing the LCMS can automatically measure pavement profile at a fixed lateral offset from pavement markings, negating the impact of driver wander, reducing re-runs in the field, and improving profile repeatability.

Profiler certification is considered the ultimate test of pavement profiling equipment. As such, profiler certification is often required before a State DOT will permit the use of a specific profiler on official statewide data collection or construction Quality Control projects. Auburn University’s Pavement Test Track (NCAT) is one of only three sites in the United States which has both the necessarily facilities and expertise to certify pavement profiling equipment.

The comprehensive NCAT certification process applies AASHTO’s R56 industry standard and includes three dense-graded mix pavement sections; smooth, medium-smooth and rough profile, as well as a smooth open-graded mix test section. All profile data must be reported in ProVAL format, and for dense-graded mixes, profilers must demonstrate 0.01 inch precision on height measurements, 90% accuracy when compared to ground-truth, and a 92% run-to-run repeatability. The open-graded certification requires first a pass of the dense-graded mix sites, and then ten repeat runs with IRI in each wheel-path reported to within just 5% of the ground truth.

The certification process required Michael Baker staff to travel onsite with their LCMS-equipped scanning vehicle and collect, process, and report, profile data according the stringent NCAT requirements. Michael Baker Engineers were successful in their efforts and received a full pass from NCAT for their LCMS profile data.