This study aims to develop an innovative prototype system implementation of untethered, contact-free, reference-free, railroad tunnel measurements (surface and subsurface) that improves railroad safety. The unique concept will inform and optimize railroad tunnel asset life cycle cost decisions. The product application will provide GPR and LIDAR measurement capabilities via an efficient, specialized Unmanned Aerial Vehicle (UAV) deployment. It will measure areas of moisture/water entrapment (behind the tunnel liner), tunnel wall liner thickness and reinforcement geometry, tunnel clearance dimensions, and tunnel material properties. Relevant metrics SATES will evaluate are a function of moisture build up, geometry (tunnel clearance), and material properties impacting fire survivability and more. The project will uniquely integrate, operationalize, apply, and field test the subject Safe Automated Railroad Tunnel Evaluation System (SATES) technology. Results will uniquely address systemic railroad needs to improve overall railroad safety and maintenance related life cycle cost decisions.