I pay the normal hourly wage one-way for travel in my vehicle, $20. for food and cover a motel room for up to 3 employees if there is a 3 bed unit or roll-out bed available. $20 seems cheap for food but they would have to buy food at home anyway. I bring an ice chest with gallon milk jugs full of ice and Ma's home cookin. Rarely ever eat out and since the movie Supersize me I avoid fast food with a passion.
As long as employees are making at least minimum wage for all travel time then you're covered in case someone has an issue. If they travel during normal work hours you have to pay them travel time. Most employees realize that business is competitive and if they want to work sometimes they have to go to where the work is.