Most bridges here do, and often when one needs to be demolished and rebuilt, the military blows it up just for practice.
Edit: Source for the sceptics
The deep demolition, which became a central element in Finnish post-war demolition tactics, and especially the development of readiness to counter surprise attacks that emerged as a threat scenario in the 1960s, received significant support immediately after the wars. The decision concerning structural demolition preparations for bridges was made on January 15, 1946. These preparations meant building charge wells, charge chambers, charge pipes, and charge hooks. Authorities responsible for constructing bridges were required to include the aforementioned structures in their plans, which significantly improved the readiness to destroy the bridges.
If it was not possible to place the charge space inside the abutment or pier, charge hooks could be embedded in the supports during the casting phase, to which the charges could then be attached.
Thats the same design the bridges here in Austria/Vienna over the Danube have; cold war planning was to delay while our military retreats into the mountains, the plains were thought to be indefensible. Looking at Ukraine will have changed a lot of minds regarding defense planning.
Not necessarily. Drones can level a position or terrorize civilians, but you can't securely hold that position or occupy territory with them. For now, there is no replacement in that job - your infantry and armor are still doing that work.
Having been in Tyrol many times, I feel claustrophobic retreating into the mountains. It's basically a funnel. How is it more defendable in modern warfare tactics?