1. Why is there still ETD baggage screening going on? There have been a number of airports that have gone to in-line baggage screening, freeing up CTX or L3 machines from those airports. Also, TSA has had 4 years to acquire more machines. (Open bag, closed bag, and open bag aggressive ETD screening was allowed as contingency back in 2002 as there were not enough CTX or L3 machines to do the job at the time.)
DTW comes to mind. They have a bunch of TSA baggage screeners standing behind airline check-in agents doing closed bag ETD testing and open bag ETD testing if the bag is small and doesn't have a lock, TSA or non-TSA. A few bags get a special X-ray tag, which results in the bag being sent to a CTX machine. It seems like adding more machines would increase throughput, making screening more meticulous and efficient. Also, personnel could be cut.
2. A new airport in Bangkok opened last September. It has state-of-the-art, in-line baggage screening, using 20+ CTX machines, the exact same machines that the US uses. No bags have to be unlocked or require a special lock. Passengers are simply paged if security wishes to search a bag. It has been argued that TSA searches bags without their owners' presence because of a time constraint to deliver the bag to the airline, too many people would be paged on a regular basis, and searching for the owner takes time. So that would imply that alarm rates are higher in the US.
Does this imply that BKK baggage screening has lower standards than the US? (i.e. The US has a broader criteria for physically inspecting a bag based on a CTX scan?)