I don't know how these sand traps on the side of the track are in real life but one thing I know for sure is that if the sand would be so deep you're not able to move, your car would by the way roll over when you slide sideways in it?
If the physics of the ground in LFS allowed a car to, then yes. But it doesn't.
The gravel in LFS isn't "proper" gravel anyway - IRL the gravel is a gravel trap, it catches the car and slows it down MUCH more than it does in LFS atm.
And yes a car CAN flip if it hits the gravel sideways at the right angle (Seen it happen first hand)
Yes normal road cars, let alone low racing cars do not stand a chance of getting out of a normal gravel trap. They normally use tractors to get cars out.
NFSPS isn't that unrealistic in my evo i slid onto the sandtrap sideways and the car just went flying over onto the roof and the sandtraps slow the car down.
Whenever anyone mentions Evos crashing, that is the video that comes up. From that I deduce that not many crash, and therefore the driver who manages must be REALLY bad at driving.