I was reading the threads on the net money and was surprised on the gas expense of shoppers. So I'll share how I keep mine down.
I am performing shops for two days on one bus line. I pay $20 for a 7 day pass. Wednesday I was fortunate: I did 5 similar CS shops for auto parts. Interestingly I did two different companies which had stores within a block of one another. Jump off the bus, do two shops in less than 1/2 hour, jump back on the bus. Each required phone calls, which I made earlier from the bus. During travel times, I filled out the reports.
Only hitch was that I did the wrong scenario on the one side of town. I traveled to the other side to finish two shops and a restaurant. Fortunately the one that I screwed up on was a 24 hour store. But I did not return home until after 11 PM.
Today I kind of repeat that route. I am downtown, just finished four shops and at a coffee shop (non-shop). I will travel for a revealed evaluation of a healthcare presentation after which I do three retail shops and a dinner shop. Then off to the other side of town to perform two more auto parts shops and three department store shops (all in the same location).
But the time I get home at 9 PM, all I have to do is data entry, scan or photograph of my POV's and receipts. Total transportation cost? Less than $4.00. Total fees? $160.00 with $50.00 reimbursement. And down time in between to do what I want to do.
Do not read so much, look about you and think of what you see there.
Richard Feynman-- letter to Ashok Arora, 4 January 1967, published in Perfectly Reasonable Deviations from the Beaten Track (2005) p. 230