At least the roadwork on interstates (and we are primarily talking about radicals taking over interstates for protest, remember?) around here is done at night as much as possible, when traffic volumes are much lower and one can close a couple of lanes without disturbing traffic too much. They use these very bright floodlights that make the work site as bright as daylight. I thought it's done like that elsewhere as well - it would certainly make sense. But perhaps the Georgia DOT is just smarter than DOTers up where you live.
But even when it has to be done during daytime and lanes have to be closed for days (thus severely impacting traffic) the difference between road work and protesters blocking highways is like between a surgery and stabbing. A surgeon (like a stabbist) cuts into your abdomen, but he does it in order to repair some damage and the cutting is necessary to the process, while a stabbist merely wants to damage you. A surgeon uses sterile and sharp implement to minimize damage, while a stabbist would use any knife available and might even twist it to increase damage.
Yes, both cause damage and pain and inconvenience but they are as far removed as road work and protesters blocking a highway just because they don't agree with something (like a police officer shooting a thug in self defense not getting indicted).
Nor are parades--our local parade is on the busiest section of the busiest street in town.
But not the middle of the interstate or other vehicle-only highway, right? And what day is your local parade held on?
Marathons are not scheduled around traffic but around people's work schedules to get the max participation.
Which means weekends or holidays when traffic is also lighter. Peachtree Road Race is on 4th of July, NYC Marathon is on Sundays and the Boston Marathon is held on Patriots' Day, which is a holiday in Massachusetts. And none of them are held on interstate highways. And the organizers pay the city.
Oh and you might consider reading up a bit on civil disobedience. You can do that, right?
What in particular would you like me to read up on? How being angry about something (policing or Trump election or a pipeline now, but why not also abortion or gay marriage or election of President [Democrat TBD later] in 2020?) entitles you to break the law and piss everybody around you off?