suspension length
The total deck length supported by cables in a suspension bridge or cable-stayed bridge.
The suspension length of a bridge is the total length of the deck where it is held up from above or from the sides by cables. It applies only to suspension bridges and cable-stayed bridges. It can include sections spanning land and/or water.
Three different figures are all published as the length of a bridge, and they rarely agree. The main span is the longest single gap between piers, the total span is the whole deck clear of the ground, and the suspension length is only the part held from above. A record-breaking bridge is usually breaking the main span record and not the others.
The approach viaducts are outside all three. A source quoting a length far above the total span is measuring from the first ramp, which is a fourth number again.