you said friends' "kids"
how old are these "kids"
what type of rig will they be traveling in?
How experienced are they?
We don't like truck stops due to the noise. Flying J's sometimes have RV parking spots away from the semi truck parking. A bit quieter. We prefer Walmart parking or Cracker Barrel. Even Walmart parking lots can be dangerous if they aren't aware of their surroundings. Lock the doors and don't open them for anything. Park in a well lit area not too far from the door. Park in a Walmart that is open 24 hours. Park near one of the poles with the video camera. If they use their heads they will be fine.