How small are the pools where people don't expect to share lanes? The largest pool at the place I go to has maybe ten lanes and I'm trying to imagine the riot that would ensue if people were told that they had to wait for their turn. There's another pool there that's used for swimming laps but it has even less lanes and the place has something like a thousand visitors a day (though not everyone swims laps, of course). Fortunately the large pool is 50 m long and the lanes are wide enough that passing isn't a problem. I go there every week and I haven't seen any problems.
Where does Carrotte live?
My town in 7000 residents and has a lovely commuity center with a pool about eight lanes wide. The treadmills overlook the pool, and I have never seen more than 4 people in the pool at one time except when there are classes, and only had to wait for a treadmill once. (I never went on a Saturday AM, but there is a signup sheet for that.)
We have a Walmart, and I have never waited in line behind more that 5 people, never had to wait for more than one at the quilt shop, and only twice have not been seated immediately at a restaurant. We have never had trouble finding a parking space, either in town or where businesses have their own parking (Walmart, Tractor Supply, etc.)
These stores are doing a comfortable business. We've only had a couple close because of financial failure - one only sold deep fried pies and ice cream, another was too high scale for a town this size and demographics with $14.00 salads and very limited menu.