Temporary CDL Drivers

What do owner/operators and independent drivers do to keep their trucks running when they need time off for a vacation, family or medical emergency or other situations? Is there a problem (with company regulations providing o/o's their authority, or insurance issues) that prevent a substitute / temporary driver to drive the truck and earn money to pay bills such as truck payments, insurance and other big expenses that are constant whether the truck is parked or rolling? I have yet to find a service that matches temporary drivers to owners who need a break... or to help owners find a team partner to help during peak seasons.

I suspect there are other drivers like me that may not want to commit to long term company jobs and who may want to experience hauling different kinds of freight - driving different types and models of trucks - driving different reigons of the country, etc... without jumping from company to company.

Thanks