(24 Apr 2020, 8:52 am)idiot wrote Years ago when i used to travel to Washington a lot 4818 in 2002 and 2003. Not sure on bus type etc.

Pure guess, but I think it would have been a Lynx.
Thought they had all gone by 2002/3.

Edit: https://www.flickr.com/photos/77000628@N02/38665521472 acquired from Redby