I recently had a vendor attempt to charge me for their travel time. I was quite surprised because no one has ever tried that with me before. I have had plumbers and electricians state that there would be minimum charges for them showing up. But when I call them I actually have work for them so it is never an issue.
But no one ever tried to get me to pay from them to just show up and do their job before. It seems almost like charging for a quote to do a job.
Now, I travel to my clients places of business as a matter of course. I have never believed that I can add as much value pontificating from my cave as I can by going into the clients offices and seeing how their office and information flows.
While in my car I do not have billable time, but I am able to stay on top of some communications. I return calls and check in with clients as well as the office.
While it may not be the overall best use of my time, I personally feel it is valuable to my clients. But I cannot believe that I would ever consider billing them for getting to their office, any more than I would bill them for having to drag my ass out of bed in the morning to go see them.