simon_n10, thank you for the confirmations. I checked the WMATA site and they do still let you leave one time with a negative balance (it's collected the next time you use the system). Though there's potential for abuse I suppose, if you could drive the negative balance past £3 it would be cheaper to toss the Oyster card than pay, but I would think for the improved traffic flow and customer relations, not to mention discovering you had too little in your pocket to get out of the station, it would be worth offering.

astralclouds, more options always welcome, thanks.

=aw