I work at a firm that routinely charges full rate for our travel time. Often we bring items/evidence back to our downtown office from a job site. Evidence always has to come to come to the office for preservation and storage. Individuals may choose to go straight to a job site from home and then come into the office; go to a job site from the office and return home instead of coming back to work th esame day, etc. The permutations on this are many.
The question is: should (or can) the company charge clients in the most consistent fashion, that being travel time from the main office to the job site and back to the main office in all cases. This would ensure that every client is billed the same amount independent of who is doing the job and the travel fees/time/mileage are fixed by the mileage from the office to the job site.
The alternative is to not charge round trip time and mileage but to have each individual charge from thier home if that is where they started or ended the travel. If one starts from home then the billabel time/milage is from home to the site and back to the finish point, wither home or office. Keep in mind that in this scenario, the cost to the client may be less but not necessarily. Also, the amount charged to the client would vary depending on where the individulas live relative to the office.
This has become a little thorny as some feel that any time one goes home, the job travel is complete and trip in to work the next day should be considered normal commuting. Keep in mind that the side trip to/from home NEVER adds to the totals of the round trip form the office to the job site.