So if you're doing 5 jobs, 1 hour each and 20 mins travel between, that's 1hr 20 min travel (excluding getting there and leaving the first and last job) you would need to be paying them over £1.50 above minimum wage for this to be fair.
Would you want to not be paid for an hour and a half of your time??
Sorry if this comes across as rude, it is not my intention, I just know I probably wouldn't take a job where they didn't take that into account.