So I just heard on the TV about the trial on technology on the Boston subway that tested passenger fingers for explosive residue when they purchased their tickets. Thankfully the test failed (hospital workers triggered false positives) but Homeland Security Department and local transit officials haven’t given up on the idea of fancy security precautions for subways. Indeed it appears DHS is spending a sizable amount of money on technical solutions (and cute dogs) to secure the nations rail system.

At least for airplane travel the particular vulnerability of airplanes to even small bombs justifies some security screening. True, as far as security goes, after 9/11 we should have reduced spending on preflight screening as the terrorists are aware that the passengers would never allow a plane to be seized again¹. Still one could make the implausible argument that TSA spending is still justified as security theater to reassure the public about airplane safety. However, the security measures for the subway don’t even have this justification as (except for a brief time after Madrid) people seem perfectly comfortable taking the subway without them and they are even less effective in preventing terrorist violence.

The train system is just one place where many people gather. If we implement effective security measures in the subway terrorists will just explode their next bomb at a march or political rally². As silly as it is to try and implement fancy security in out subways at least they are a small enclosed space that might net the terrorists a few more bodies but spending spending 13.6 million on Amtrak, which isn’t usually a tight squeeze, is even dumber. Worse the security measures the DHS wants for the subway wouldn’t be effective even if they worked. If we scan fingers for explosive residue when tickets are purchased terrorists just wouldn’t buy a ticket. Either they would get a monthly ticket, have a clean associate purchase their ticket for them or simply jump the gate. It wouldn’t be too hard to get some associates to start a fight or jump the turnstyle themselves to distract the cop or just look at the train schedule and outrun the cop to the subway³.

Now some simple measures (confiscating abandoned bags) might be cost effective and if it turns out that subways are particularly vulnerable to simple poison gas attacks maybe some very accurate detector could be helpful though usually the simple fixes that generate other benefits (like better in car ventilation) are the best. Hell, I can even see the argument for some sort of technological surveillance technology, e.g., some system that quietly gathers data on who has certain chemical traces, but the transportation security measures that the DSA is pursuing are just dumb.

This isn’t just a simple matter of government waste. There are real risks we face from industrial accidents, terrorism and natural disasters that effective government spending could minimize. The reason 9/11 worked is that the terrorists struck us in a way we weren’t expecting⁴ and there is no reason to think they have some sort of transit fetish that will prevent them from trying to poison the water supply, attack a chemical plant, or instill panic with a dirty bomb. Unfortunately the democratic process rewards congressmen who play to the human tendency to overestimate the risk of past disasters and the nature of bureaucracy rewards better ways to do more of the same more than suggestions that it isn’t worth doing. But until we can fix the system so the funding goes where the security experts recommend instead of where people’s gut tells them it should I don’t have much hope of things getting better.