The riders are expected to enter Loudoun County from Maryland at 2 p.m. with theGranted Route 15 from MD to Leesburg is a 2 lane road with a 45 mph speed limit, and the routes Rolling Thunder takes are wider. Usually the pictures of Rolling Thunder show a double column of motorcycles, so say 2,000 cycles an hour can pass a given point. That means RT must take 25 hours.
final riders estimated to enter the county between 3:30 p.m. and 4 p.m. The Loudoun
County Sheriff’s Office and the Virginia State Police will be stopping traffic at the
intersections on Route 15 from the Maryland line to the Leesburg town line
I'm not aware VDOT has ever issued an alert for Rolling Thunder, although to be fair that's not on a workday.