Ritu Narayan founded Zum after struggling to find reliable school transportation for her children. Today, her $1.7 billion company is bringing 21st century technology to a stodgy workhorse. “Transportation is not just a logistics problem; it’s basically an on-ramp for students to learn,’’ says Narayan. Read the full story about how this entrepreneur built Uber for the yellow school bus: 📸: Cody Pickens for Forbes #ForbesOver50#