the ones = stairs?

Unfortunately, most people / who live in cities / are too busy to spend a lot of time / outdoors. The fact is / that, whether it’s at home, work or school, they spend almost 90% of their time / indoors. That’s why architects are working / to create buildings / that encourage more physical activity. One strategy is / to create stairways / that are comfortable to use, easily accessible, and look interesting. Another strategy is / having skip-stop elevators / that only go to certain floors, / forcing people to walk to the ones in between.

thanks in advance