I regard myself as a "willing to help anyone" person (and people have told me that I am such) but it has got me into situations of being taken for a ride (no pun intended!) such that I've started to wish I never offered in the first place. If it becomes a regular thing it is difficult to get out of it when you need to, and if you have a change of plan you can feel guilty at having to tell your passenger at possible short notice.
There are a few close friends that I'd drive anywhere, anytime, but they are also people who wouldn't ask unless they were stuck, so that never becomes a chore. Also, if people don't abuse your offer it should make them more comfortable in asking again when they are stuck.
I'm on a couple of local charitable committees and two others close by sometimes share lifts, but it's only twice a month.
Hubby recently got into a situation he felt was uncomfortable. A long-standing acquaintance asked for a lift to a hospital appointment. DH assumed it was a one-off and willingly agreed. The hospital was 25 miles away in the middle of Manchester. Okay for a one-off. But he was asked again a month later, and again.......and again. And then to drive the wife to Chesterfield hospital, a similar distance, and again.....and again. Suddenly he had become a free taxi service, on demand. True, they bought him a cuppa in the hospital cafe and gave him a fiver for fuel (ha, ha), and the wife gave him a houseplant for me.
Both destinations are accessible by public transport, albeit needing a change from train to bus (or taxi). Plus we have Community Drivers who regularly volunteer for such help to pensioners/disabled etc.
It would have been better if the couple had asked a few different friends (and remember we were only acquaintances) to spread the load and avoid the ill-feeling.