If you're traveling and need a shower, you often have a few options:
- Truckstops
- Campgrounds (some offer paid showers to non-campers)
- gym membership (planet fitness is a go-to for this)
Here's [a directory of public showers](https://publicshowers.net/) in the US. There are others, but they seem to be riddled with ads so I won't link to them here.