Be careful - I found out that breakdown policies often do not cover driver illness.
I was travelling solo from Cardiff to Essex, and during the journey became ill. I was becoming steadily worse and when I got to South Mimms Services decided that I was no longer well enough to drive, so I pulled in and called the AA for help.
They sent someone out - but due to crossed wires believed it was the car that was unfit to drive rather than myself. When I graphically explained the problem by vomiting in front of him, he explained that they were only insured to relay broken cars, and that technically to relay me home would therefore have been illegal.
So he decided that we would pretend that there was a fault with the brakes, and started to make arrangements. Now despite there being an AA depot at South Mimms full of recovery trucks, apparantly none of them were available, and as it was late at night it would be a considerable wait for one! So in the end I phoned my parents in Essex since that would be quicker, and they both came out so that one of them could drive me and my car home!