Takes a LOT to totally down a bridge. Hans Rudel talks about bombing one for some period in ww2 and it was up and running the next day after direct hits...mind you Stukas couldn’t carry much relative to today.
Basicaly that is what Denys Davydov says:
https://www.youtube.com/watch?v=Zhe0xpk_qTw
***Note: Youtube is punishing him. So, now he must include ads from a sponsor [1 in beginning]
How to get around YouTube Demonetization
https://air.io/en/youtube/youtube-demonetization-how-to-continue-making-money-from-your-channel
Most effective way is fire
Drive a tank truck (or several) onto the span, open the valves and light it
Already been done (By accident) = the Mcarthur freeway I 580 in San Franciso - gasoline truck rolled over on ramp
I 95 - Shelton Connecticutt , Truck with fuel oil hit overpass piling Collapsed section of bridge onto road
The direct hit on the rail cars certainly helped. The massive fire from the cars increased the damage.
Similarly well timed future strikes are highly probable.
It’s a very tenuous supply line.