bridge main span
The greatest horizontal distance in a straight line between consecutive piers of a bridge.
The main span of a bridge is the maximum length between any two supporting piers, as defined by the void between the piers' edges in a single straight line.
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.