It depends... if you fall asleep your cars not gonna suddenly stop or zoom off. It could do either or stay the same speed. The point is that you cant steer! not how fast it goes. anyway... you shouldn't fall asleep at the wheel anyway. have a cooffe or something.
Sure it is dangerous. Carbon Monoxide can seep into the vehicle while you are driving and cause you to fall asleep. Not a good thing driving down the road.
your speed sensor is failing, the speed sensor is located next to your oil filter it controls your speedometer
speed sensor
Because it does and that's okay :D
the transmission is slipping
Press the brakes or down shift
no it will slow it down
Tell them something really boring or you can try a method that calms them down while they are comfortable
If its a motor knock it will do that while sitting/reving engine not just driving. If it's only while driving try different things to check it out. Does it do it over bumps?(parking lot speed bumps are a good test track) Maybe only when cornering? Try pushing up & down on the truck while its sitting and see if it does it. Does it shake also?
Check the speed sensor
deer
my oil pressure goes up while I'm driving and back down when I stop what could cause that