High Performance Steel (HPS) has quickly gained popularity in United States bridge applications due to its high yield strength and better weldability, toughness, ductility, and weathering characteristics. However, a great deal of information is missing from the body of knowledge on HPS performance and design criteria, especially concerning HPS-70W (485W) produced by thermo-mechanical controlled processing (TMCP). This research examines material characteristics and fatigue performance of HPS-70W (485W) TMCP, as well the performance of Ohio's first HPS bridge in service. Data from 96 tensile tests show that yield and ultimate strengths of HPS-70W (485W) TMCP are dependent upon plate thickness and orientation. 75 Charpy V-Notch (CVN) specimens were tested, and all met the ASTM A709 requirement for minimum toughness. Twenty-nine specimens were tested to investigate the fatigue resistance of continuous plates with punched, drilled, and reamed holes. Results from this investigation suggest that current restrictions mandated by some state departments of transportation concerning punching holes are not overly restrictive when HPS-485W (70W) is utilized. Performance of drilled and sub-punched and reamed specimens met or exceeded American Association of State Highway and Transportation Officials (AASHTO) (2004) requirements for Category B details. Performance of Submerged Arc Weld (SAW) and Narrow Gap Improved Electroslag Weld (NGI-ESW) welded butt-splices utilizing HPS-70W (485W) were examined. All specimens performed considerably better than predicted by the AASHTO fatigue life equation.