Not sure about that. Trucks generally have very powerful brakes and can stop faster than you'd expect. Crashing into the back of a truck can be catastrophic.
Truck do have big powerful brakes, (newer ones with disk-brakes are really awesome) but it still takes a LONG time/distance to slow/stop 80,000lbs from 100km/h.
Kinetic energy is a real bitch.
There are videos of new volvos with 'automatic emergency braking' that is impressive to watch; but that isn't real-world.
In the real world during a 'panic stop' the trailer brakes lock up and the trailer starts bouncing. If you are lucky the tractor wheels don't lock up, but while you have slammed on the brakes, you are still steering and trying to avoid hitting anyone.
316ft for a car vs 524ft for a truck.[1] Almost twice the distance.
And that does NOT match my real-world experience.
I'd say on average it takes 3x-4x the distance to stop a rig.
All the brakes can do is stop the wheels; you still have way more mass generally and momentum to actually get stopped.
While crashing can be catastrophic, I'd like to see some numbers on how many crashes into the backs of trucks were because the truck out-brake'd the smaller vehicle behind it as opposed to the smaller vehicle not paying attention.
The vehicles in the lane beside the truck do not have good visibility in the area in front of the truck. If a vehicle were overtaking the truck intending to immediately go to the lane with the truck, they'll not see the vehicle merging into the motorway from the other side. Thus the theory advises one that merging behind the truck is preferable.
