Learn Me Consulting Gigs

I have recently been recruited to start some consulting work on the side as a Construction Manager.  I've worked out a fee % based on actual construction cost.  Some of the latest work will involve pre-construction services and that will be paid hourly, with some minor vehicle travel involved.  How do you consultants out there get compensated for vehicle travel?  I would assume the gov't mileage rate for you area, what about the windshield time?  Do you charge the same hourly rate for that time?  Since this is my first venture into the consulting world I'm not real sure how to proceed, I would hate to set the precedent and miss out on some easy income.  

I bill the client based on government mileage as well as hourly for the windshield time, but most of my projects are within an hour or so of the office.  It would probably be different for long distances, if for example I was flying across country to job sites.

In reply to stuart in mn :

The trips would be within an hour or two of my house.  Do you bill at full hourly rate for windshield time or a discounted rate?

The regular hourly rate.