Of course you can, but due to the volume of the tube that has to be filled, it's going to take a lot of time, unless you want a hollywood style idiot caused disaster.
Now if you can seal off discrete sections of the tube, you can reduce that volume, but those kinds of emergency seals will be expensive mechanisms to install, so don't expect there to be very many of them, so you are probably still dealing with a LOT of volume, just not an absurd volume.
Now it would probably be a lot safer and faster to use frequent emergency access ports that can lock onto a pod and airlock open just like at the stations, but that assumes you can get the pod to such a point rapidly.
All in all, it's a neat idea, just like it was when they published it way back in the 40s. (I forget whether it was popular mechanics, or popular science.) But it still has plenty of issues, and dealing with emergency situations isn't even the first in line. (Like how do you make a full sized track at a length of a hundred miles or more that is torn apart or otherwise caused to leak unacceptably due to geological movement, not just from quakes, but also from thermal expansion and even the sun tide. Half a meter every day in some places isn't something for an engineer to sneeze at, especially when they want to try and maintain a near vacuum in a giant metal noodle in those conditions. )