With breakfast finished and backpacks prepped for the day, children across Spain's Barcelona province strap on their helmets and, at around 8 a.m., head to school not by bus or car, but in a critical mass of bikes dubbed "bicibús." As with traditional bus lines, each bicibús route has stops where other cycling students can join along the way. Parents, teachers and other volunteer adults ride, too, to ensure the kids' safety. Bicibús is just a couple years old, but already more than 1,200 kids pedal 90-plus routes to more than 70 schools across 25 cities in Catalonia. (Barcelona is one of four provinces in the region, in addition to being a major city.) Biking in groups increases awareness of riders on the road, especially where dedicated infrastructure is lacking. And families around the world, from Portland, Oregon to widely promote bicycles as a healthier, more sustainable commute for all. Fewer gas-powered vehicles on the road decreases pollutants that contribute to unhealthy air. "I have been working as a teacher for many years. The children in my class who arrive by bike are more active during the first hours, more attentive and participatory," [Vilardell] says.