I can see how that could be a problem. Long base vehicle changes lanes causing a whip effect on the short base towable; not something you want to happen at too high speed.
People should test slow speed travel just once to see the difference it makes. Going 200-300 miles away at 55 or 65 and then camping for a few days the few minutes of times before arrival make almost no difference and saves a ton on gas. You always see the little sports car in traffic that cuts left and right and then it's maybe 4-5 cars ahead after 30 minutes of traffic; having saved a few seconds and caused traffic behind from everyone having to adjust speed when they get cut off.
I usually try to drive 55 but will go 60 when all lanes are going that speed as I think being in the way is also dangerous.