I learned that I need a cell phone.
I got a flat tire today going down the freeway with my two year old son and 3 week old baby girl. With no way to call for help I started walking down the freeway with my son and the baby in the front pack to the next call box.
I didn't get very far.
Everybody who went by me called for help. Two CalTrans guys came by, one tow truck, one police officer and two good Samaritans.
I also learned that a complete stranger will give you their cell phone trusting you to return it.