You mean a train station?  Yes I would.<p>Blowing up a plane/train/stadium/airport security waiting line/etc... is easy.  The "real" risk I guess is people using jets full of fuel as flying missiles.  However, post-9-11, no passengers will permit that use.  Hijacking planes is over.<p>So the scenario you describe: getting onto a rapidly moving tube of metal with a couple hundred people who haven't gone through metal detectors or x-ray machines is exactly what happens every time I take the train.  In fact, the lack of hour long security lines, having to remove my coat, belt, shoes, etc... is one of the reasons I strongly prefer the train.