Originally Posted by jackal

At yet other airports, like DCA the last time I was there, the contract BP checker doesn't have a scanner and so doesn't have a way to tell if you're PreCheck. Thus, you'll be directed to the regular elite line unless you specifically ask. At DCA, I always say, "PreCheck?" when I approach the BP checker, who then lifts the rope and allows me to proceed into the PreCheck lane. TSA then scans it, and if you don't qualify, they'll send you back over to the regular lane.