Diesel particulate filters can lead to car trouble

A UK fleet operator is warning drivers that particulate traps fitted to many modern diesel engines can lead the vehicle into limp-home mode or to breaking down. The diesel particulate traps store soot, which needs to be burned off periodically. This burning off of soot, called regeneration, happens when the car is driven at a steady speed of about 50 mph for 20 minutes. I wonder if there are warning lights for when the diesel particulate trap needs to be regenerated. For the US market, where folks aren't used to driving diesels, this might become even more of an issue when particulate traps become common place.
[Source: Reuters UK]