Any tips for making a 15 hr. drive with 3 kids and just me driving?

Soon, I’ll be driving a good way across Canada without my hubby to spell me off. My kids are older (15, 12 and 10).

I’ve driven 18 hour days before but that was when I was a teen and I had my sister to spell me off when I got tired.

I am most concerned about the first day of driving. The other days are an easy 9 hours, 6 hours, 7 hours and then 4 hours.

My plan, so far, is to take a lot of breaks. Get out of the car and stretch my legs and maybe jog up and down for a few minutes.

Anyone have any other tips for staying focused on driving and avoiding fatigue?