Penetradar recently submitted a SHRP-2 Tunnel Liner Inspection report to the Oregon DOT. The inspection included 3 tunnels, the twin Vista Ridge and Tooth Rock, near Portland. The liners were inspected utilizing GPR, Infrared Thermography and High Resolution Imaging, to produce quantitative information, including deterioration, moisture content and voids. Hammer soundings were performed at a height of six feet along the tunnel liners, GPR correlated 67% or 26/39 of delaminated areas found by the soundings in the Tooth Rock concrete liner. The scenery was amazing also.