About three miles south of downtown San Antonio, Sarah Neal's office sits on a part of the San Antonio River most people in the Alamo City don't even know about. "I love being outdoors," Neal said.

Bike 4 miles. Kayak 10 minutes. Drive 2 miles. Repeat. This may sound like the start of an athletic competition, but it’s actually 18-year-old Jonah Lee’s commute to high school. While multimodal ...