This is actually the Bougainvillea spectabilis 'Mary Palmer' (spectoperuviana group), an interesting and beautiful bicolor Bougainvillea with white to pink bracts and variegated yellow-green leaves.
The latter photos were taken when I walked across the bridge. It is interesting that one side of the bridge flowered better than the other side. What could be the reason for this? Morning and afternoon sun that differ in light intensity?
Anyway, a few links on this uncommon cultivar are shown below: