Perhaps more people should try doing this to protest.
I watched that film clip on broadcast television. The show also had three of the students that thought up and created the event.
I read your comment on the other thread and some of the replies to it and then some.
Most of the obstacles to using the drive-55 method of protest could be overcome by organization and planning by the protesters doing the driving.
For example, where the left lane is strictly for passing, have 6 or more cars in the left lane all passing the co-protestor driving the car to the right by a measly one-mile-per-hour faster speed.
Most cities have an eye-in-the-sky helicopter that has a camera crew that gives traffic reports during rush hour and for other things like accidents and.... drive-55 protestors. It's their job, how could they not report major congestion/traffic snarl.
Figure out ahead of time how long it would take the helicopter to arrive at the location of the protest and adjust the start time accordingly. At the properly calculated time call the eye-in-the-sky office and inform them of major congestion at "X" location. Perhaps stating that it appear to be caused by some type of protest.
Could have a person driving one of the protestors driving one of the cars call it in on a cell phone. Get on the CB radio and announce the event as it's happening.
The objective is to get media coverage of the protest and its cause. Perhaps get a witness to the protest on a local morning talk show, TV and/or radio.
Witness: "Yeah I was stuck behind one of the protestors. A sign in the back window said: I'm driving 68mph, if you get a speeding ticket the ticket will cost you $30 -- you'll pay an extra $275 that goes toward assistant state prosecutor longevity pay and saving the Whales. The protestors have a point. Still, I was late for work because of it."
How about this: Ted Kennedy wants to take away my 2nd amendment right to carry a gun that protects you from criminals that don't respect your rights or life.
Or, the designated spokesperson for the protestors could contact a trusted reporter to convey the protestor's message while protecting the identity of the source.