I am not kidding, I give you 2 stories....

1) I have a friend was driving on a highway with 3 friends to a big city. He did not check the coolant and the radiator before he took off. Unfortunately there was a leak on the radiator he did not know. When he was driving on highway, the coolant was too low and the engine temperature rose very fast suddenly, and he did not noticed since he was chatting with friends. And suddenly the engine stopped running. Lucky enough, he was drive on the far right lane and the car had enough speed to be pull off to the shoulder. It was a 5-6yrs old Camry.

2) Another friend was riding with 3 other friends on a highway. The car had old tires and suddenly one of them broke and went to flat. They were on the far left lane and stopped and could not pull off to the shoulder. They were lucky that two American stopped their cars on the highway with flashing lights, stopped other cars, and pushed their car to the shoulder.

You self think about if it was safe ....