I think it depends on the location. I hear that walking works in some places, but standing is what I’ve seen work.
When I lived on alms for a couple of months or so many years ago in Woodacre, CA, I received most meals at the kitchen door of Spirit Rock Meditation Center, but whenever their kitchen was closed, I went on alms in the nearby town of Fairfax (hitchhiking to get there). I disciplined myself to walk around the little town each time, but the only food I ever gained that way was (1) a small bag of peanuts once handed to me by a toddler in her stroller, and (2) a Cliff Bar from a homeless man who felt worried for me.
In contrast, food was donated in great abundance whenever I stood outside the door of town’s only health food store (with the manager’s permission). When the store wasn’t available one day, I stood quietly outside a Thai restaurant (not daring to knock as calling attention to oneself isn’t their tradition); fortunately they saw me just before my lunchtime ran out, and filled my almsbowl.
When I lived in Greenville SC (2003-2011), if the planned daily food dana delivery failed, then I went for alms in my neighborhood. That actually meant either phoning one or two of several friendly neighbors, or going along knocking on doors - otherwise no one would ever know that I was out there. When telephoning a neighbor, I would say politely, "Is this a good time for me to come by with my almsbowl?
The only time I walked outside of that neighborhood for alms was one occasion, when another bhikkhuni was staying with me. Standing gained us nothing; the only grocery store in walking distance refused permission to stand near it, so our standing was limited to street corners and random places. Nor did walking succeed, until one man called to us from his car; he ended up getting pizzas for us. We walked back with 2 big pizza boxes proudly covering my almsbowl.
At my Vihara in Charlotte (since 2013), I haven’t felt comfortable enough to knock on neighbor’s doors for alms; my neighborhood doesn’t feel as friendly that way. The only time I walked for alms in uptown Charlotte, whether we walked or stood, no one looked at me and the white robed nun who came along, not even a glance; it was chilling. I never tried that again.
My food here is brought daily by various donors organized by a volunteer - except when that plan falls through, which happens once or twice a week. Then I may depend upon my mother (92 years old and still cooking!) who’s not far away, or a nearby friendly Vietnamese restaurant. If nothing else works out, my meal comes from any of the restaurants that I can reach on the local bus and for which I have a donated gift card (usually Panera Bread).