Most platforms would need extensive redesign, rebuilding to incorporate the barriers. Many are just precast concrete planks on brick or concrete piers. These were upgraded from timber structures originally. Therefore they comprise a ~100mm thick concrete plank with some blacktop and a void under. Some may be backfilled but to put barriers up a concrete foundation block or minipiles would need to be installed under each post to resist the horizontal forces. This is fine for new lines but would close half the network for upgrades to platform barriers.
