It depends on the specific insurance policy of your friend. In general, most car insurance policies provide coverage for anyone who drives the insured car with the owner's permission, as long as they have a valid license. This means that if you drive your friend's car on a road trip and get into an accident, their insurance should cover any damages or injuries that occur, up to the limits of their policy.
However, it's important to note that some insurance policies may have exclusions or limitations for certain types of drivers, such as those with a history of accidents or traffic violations. Additionally, if you don't have your own car insurance and you're involved in an accident while driving someone else's car, your friend's insurance may not cover all of the damages or injuries. In this case, you may be personally liable for any expenses that exceed the limits of your friend's insurance policy. Therefore, it's always a good idea to check with your friend's insurance company before driving their car to make sure you're covered in case of an accident.