Based on 2017 statistics, the U.S. has 614,387 bridges in which 40% are 50 years or older and 56,000 (9.1%) of bridges were structurally deficient. One-third of Canada’s 75,000 highway bridges have structural or functional deficiencies and short remaining service lives. Hong Kong has 1,340 bridges, of which 7% and 40% are above 50 and 30 years old, respectively, now showing several signs of ageing. Québec bridges have reached 72% of their service lives. Therefore, due to limited funds and public accountability, transportation agencies need to have a firm foundation in making justifiable intervention decisions. This cannot be done without reliable model(s) for bridge superstructure condition assessment using non-destructive technologies (NDT), such as Ground Penetrating Radar (GPR), Infrared Thermography (IR), and image analysis. Interpretation algorithms for NDT results as well as bridge deck corrosiveness model and rating system will be presented. The developed approach is believed to help transportation agencies identify critical deficiencies, take informed decisions and focus limited funding on most deserving bridge superstructure.