What do you mean?
Like a highway of cars driving at speeds over 150 passing on the left and moving right and left to pass, repeated?
Or a guy in a 1000 cc sport bike trying to run from a cop in some souped up muscle car and the guy in the bike is trying to exceed 250 with an officer in some wild muscle car trying to race around cars on a 3 lane that are all going between 100-130 km/hr.
Big Difference! 
I have said this many times before.
Speeding like this on a crowded highway is very dangerous, trying to weave through traffic at 150 when everyone else is at 110 cause there is so much volume or cause people are blocking passing lanes.
But when the road is open in the middle of the night and your going 150 in a straight line, no this is not dangerous.
There is a big difference between speed, and a high speed pursuit of a criminal when the road is maxed out volume wise.
I mean sure if officers want 700 hp cars to run after criminals on the autobahn at 2 am go for it.
But i sure dont want the OPP with vehicles like this on the 400 at rush hour trying to go after some guy on a sport bike who wont stop.
It also bothers me people never refer to speed and the road. I mean speeding 50 over in a school zone or in downtown toronto at 9 am is alot different then driving down the 400 to barrie at 6 am on a saturday no?