Another typical political reaction to the European attack attempt. I went through this after both the London and Madrid attacks (which were unfortunately much more successful), and we did a number of important things to improve security on trains and in terminals. I will not go into details, but with adequate training and personnel, these can be very effective.

Fortunately, the impacts of attacks on trains have not been as successful for mass casualty incidents, because it is difficult, to overpower so many people on multiple cars (bombing has been most successful for casualties, but are more difficult to pull off) with folks now properly conditioned to resist, as we just saw. Putting this risk in perspective is important, since you are in more risk of death from driving to the train station, than from all of the terrorist rail attacks combined, and we are not even seeing politicians proposing harder driving tests.....

There is just no effective way to properly screen the volume of rail passengers at an airport level of security (one boarding point) for transit rail, commuter rail, or intercity
rail systems, without massive delays. More security may have helped deter attacks (but we really don't often know?), but there is little evidence to suggest that more "airport" type screening would help much. Remember, that the deadliest Amtrak terrorist attack believed by some to have been committed by domestic extremist elements and still unsolved, derailed the train by sabotaging the track.

Thankfully, trains are difficult to get off of the ground to crash into other targets, and so the "taking" of the train, does not also make it a "weapon", as we saw with airplanes on 9/11. If I were still involved in this planning, I would have more worries more about industrial rail targets, once again, without going into details (we don't want to "red team" these things like this in public for a reason....).

What we really need to build is a wall around the middle east to contain these infectious terrorist ideologies. All persons, money, equipment, and communications, needs to be cut off at the borders so these folks are isolated. This is also so that the propaganda and terrorist recruitment is cut off. That would be a better use of my scarce tax dollars, by dealing with the "roots" of the middle eastern terrorist problem, than wasting these scarce resources on security screenings that may not have much impact, other than to show that "politicians" are somehow "protecting" us, with these very costly, but generally ineffective, security screening measures.