Yippee, got my June travel expenses for Coasties, this time we had been warned they would be late.
Volunteeers should always claim their travel expenses, the organisation needs to know how much volunteering costs, and if you don't the idea will get around that you shouldn't and then only rich people will volunteer.
You can always give it back as a donation. In fact this can be better for a charity, because donations are unrestricted, i.e. the charity can use them in any way that their aims permit, a lot of any charity's income is restricted to a specific use by the grant giving body.
Most of my visits to Leeds are on the bus, with my trusty bus pass, but getting to remote parts of the North Yorks Moors is not so easy by bus, so the car it is. Still at 25p a mile it's not exactly making you drive if you don't need to!