But I would definitely buy coffee from a vendor like this. What other captive markets could you sell coffee to ? Where do people wait in line a lot ... Texas DPS would be a gold mine.
Train stations and airports. Onboard trains. Amusement parks. Maybe not a lineup, but anywhere people gather, such as city parks and tourist attractions.
The first time I saw this setup was actually in the 80s. I was skiing and one of the hot chocolate companies was sampling a new product. There was a guy, on skis, at the entrance to the lift line handing out samples using one of these thermos backpacks. It was styrofoam cups in the cup dispenser back then of course too.
Either way, there is something really compelling about having a hot beverage brought to you right when you need something. I can see the appeal of having this service in a traffic jam, now only if they could figure out something similar for bathrooms.
Someone handing you individual sheets of paper on demand?
I can’t think of a place less congenial to anything edible/drinkable than a bathroom. Yuck!
Either someone would get hit by a car and the resulting lawsuit would end it, or the city/police would end it. While "it is done" as far as traffic vendors, it isn't done for very long for the forementioned reasons.
Nice idea. I have seen a novel (to me at least) system when visiting Boston, a city of traffic jams:
People wearing a metal contraption on their backs that makes them look like ghostbusters. In one hand is a hose from which they can fill your cup; on the other side is a tube of paper cups if you don’t have one. They just walk through the traffic jam (I saw this at the end of the tunnel leading to East Boston) and driver would wind down their windows.
On one hand your scheme has much less labor, but this approach can serve many more, and captive, customers at a high density time of day.