Plenty of places operate much more dense transit without that level of security.
Trains, even HSR have essentially zero hijacking risk relative to airplanes, and proper safety interlocks make them very difficult to use the vehicle as a weapon.
At that point, your terrorism risk is approximately on level with any other dense transportation interconnect.
Trains, even HSR have essentially zero hijacking risk relative to airplanes, and proper safety interlocks make them very difficult to use the vehicle as a weapon.
At that point, your terrorism risk is approximately on level with any other dense transportation interconnect.