Adventure tours, a subset of over-the-road tours, involve smaller groups and more active experiences, from trekking in Nepal to whitewater rafting in the Grand Canyon, whatever helps guests experience more intimately the people, culture, and geography of a particular area.
In this type of tour, 16 or so people may bicycle from one interesting place to another, while the team leaders drive the support van, accompany the riders, fix the food, set up tents, and take care of the tour details so guests can focus on having fun.
These kinds of jobs are for the physically fit and adventurous. You may spend time loading bicycles over your head onto the top of the van, carrying rafts to load on trailers, hiking miles a day. And that is on top of the camp set-up and tear-down, as well as food preparation and clean-up.
The payoff in scenery and adventure will be high, in wages, perhaps not so high as bus tours. If you are serious at all about doing this, you likely are passionate about it, and this is a good place to live out your passion. These kinds of trips can take you all over the world.