How do 13-year-olds envision the ideal city for aging in the future? It will include multigenerational housing, all kinds of autonomous vehicles and lots of cool technology to track health and help keep residents safe — such as robot caretakers, self-balancing shoes and a bionic suit that deploys airbags when the wearer falls.

Those were some of the design suggestions offered at the 26th Future City Competition that was held in Washington, D.C. The annual contest — featuring a different focus each year — challenges middle school students from around the country to come up with a plan for improving the world. The 2018 contest asked the kids to envision an “age-friendly city” 100 years in the future. Some 40,000 students participated, with 600 students from 44 teams making it to this prestigious final round of competition.

It’s a serious contest that would be daunting for many adults. Kids are required to come up with innovative solutions to issues such as how their imagined city would get its food supply, offer efficient transportation and control waste — as well as find ways to keep the older residents happy and healthy. To qualify, they submitted a virtual city design using "SimCity," the city simulation online game; a 1,500-word essay explaining their plan; and a scale model of their city built with recycled materials. Many of the kids said they had spent 200 or more hours of work on their projects, with the oversight of mentors, over the past several months.