Zn-based coatings delay corrosion, while local steel condition and loading determine the mechanical response of bridge wires. This critical evidence appraisal uses 61 selected study families to clarify what coating, hydrogen and fracture measurements establish. Tested products differ in when visible red rust or brown products appear. After steel exposure, fatigue tests assess a different response: with a prescribed 100 μm deep cut, mean life at a stress range of 360 MPa was 203,498 cycles in air and 85,538 cycles in 3.5% NaCl spray. Controlled charging and desorption establish hydrogen-sensitive mechanical responses in the tested pearlitic states; selective desorption distinguishes the mechanical relevance of retained populations. Matched pre-corrosion comparisons and contact tests show why continued wetting and local contact conditions matter. These comparisons guide evidence selection for the observed wire state and response being assessed. The synthesis is interpretive; cable assessment also requires spatial exposure, restraint and load-transfer information, with validation matched to the intended mechanical output.