Is Driving like this any safe?

Dumb question: but I was in truck with another team driver just down WV @i90 highway last week and he's only 8 month experienced driver however I just started as driver so I'm still learning. My team driver drove the truck like a Nascar literally kept his speed around curviest curves @ 70-85 miles and repeatedly reminded me to do same. I DID NOT find that safe at all because I have a fear of tipping over the #### trailer if it goes out of control due to speed. His advice was to keep the truck going in same speed by going over the rumble strips when road curves to the right and go over center lane when curvy road going to the left to keep the speed momentum flowing. Basically carry the weight of the truck in direction its going. I think that's unsafe because other vehicles can get in your way especially when it's pitch black out there and second speeding is dangerous. Experience drivers please share your opinions I'd like to know if that's how it's done??

 

Thanks. I will do that

 

That's exactly his attitude.

 

I will do that thanks