Oddly enough, this is the first I have heard the FRA is going to relax safety regulations due to the installation of PTC. Granted, I don't follow this very closely, but close enough. And frankly, I think it would be woefully irresponsible for them to do so. Sure, PTC is going to improve the safety of passenger (and freight) rail, but I don't think it is sufficient to completely mitigate the risk. One can certainly see from accidents in China and Germany using these lighter cars that while the occurrence of accidents might be reduced using PTC, the effects are magnified.

The article states "Europe and Asia have realized the benefits of lighter and more nimble trains – cost, speed, and energy consumption among them – but Amtrak’s planned purchase is further proof that the U.S. is not quite there yet." Such an analysis fails to consider the primary reason we have these weight regulations - for the safety of the passengers on board. I don’t think the US has failed to realize the benefits of lighter trains, but it is Europe and Asia who are "not quite there yet," putting cost, speed and energy consumption before safety and ultimately the before the lives of their passengers. Comparing studies by the FRA and the EU shows a dramatic difference in passenger fatalities. For example, in 2008, 2848 people were killed in rail accidents in the 27 member nations of the EU, with 17.4% coming from passenger rail deaths ~ approximately 500 people in one year. That translated to 2.03 passenger fatalities per billion passenger-miles traveled. In another study of commuter rail fatalities conducted by the FRA, between 2000 and 2006, the US averaged 75 fatalities per year – almost 38 times less. And that is ALL commuter rail related deaths – passenger fatalities averaged 4% of the total, or 3 per year. That is 0.36 deaths per billion passenger-miles. So for some reason, the Europeans are experiencing 5.6 times more passenger fatalities per billion passenger-miles than the US. I am not sure we want to emulate their practices too closely.

There is a joke I hear in the RR community regarding third world railways. They don't operate passenger trains for moving people, they use them for population control. Perhaps there is more truth to that than we give credit.