Corrosion is the greatest problem facing steel bridges today. Corrosion is caused by the interaction of steel and atmospheric conditions. It can be prevented by adding a protective layer to the steel or by using a protective steel, collectively known as corrosion protection systems. The purpose of this study is to evaluate the performance of six of the most common corrosion protection systems: uncoated weathering steel (UWS), uncoated stainless steel, galvanizing, metallizing, 1-coat inorganic zinc paint, and a 3-coat organic zinc paint system, in relatively corrosive environments. The severely corrosive environments considered in this research are coastal environments where natural chlorides are present and environments where chlorides are present via the high use of deicing salts. Performance was evaluated first through a statistical analysis of existing field data and subsequently through implementation of laboratory accelerated corrosion testing on each of the corrosion protection systems for 80 cycles, representing 80 years in the field. The statistical analysis of field data showed the relative ranking in order of descending performance to be: galvanizing, UWS, then paint, with metallizing having variable performance over different age ranges; this ranking was affirmed by longevity estimates determined through laboratory testing when lower, more conservative percent mass loss and percent rusted benchmarks were used to determine the longevity estimates. Stainless steel corroded more than expected during laboratory testing and requires further investigation. The implications of the longevity estimates show that steel can provide a long service life even in a relatively severe environment. Use of any of these corrosion protection systems can improve performance, increase service life, decrease required maintenance, and provide economical steel bridges.