Ismael El-Amin was driving his daughter to school when a chance encounter gave him an idea for a new way to carpool.On the way across Chicago, El-Amin’s daughter spotted a classmate riding with her own dad as they drove to their selective-enrollment public school on the city’s North Side. For 40 minutes, they rode along the same congested highway.“They’re waving to each other in the back. I’m looking at the dad. The dad’s looking at me. And I was like, parents can definitely be a resource to parents,” said El-Amin, who went on to found PiggyBack Network, a service parents can use to book rides for their children.Reliance on school buses has waned for years as districts struggle to find drivers and more students attend schools far outside their neighborhoods. As responsibility for transportation shifts to families, the question of how to replace the traditional yellow bus has become an urgent problem for some, and a spark for innovation.State and local governments decide how widely to offer school bus service. Lately, more have cut back. Only about 28% of U.S. students take a school bus, according to a Federal Highway Administration survey concluded early last year. That’s down from about 36% of students in 2017.Chicago Public Schools, the nation’s fourth-largest district, has significantly curbed bus service in recent years. It still offers rides for students who are disabled and homeless, in line with a federal mandate, but most families are on their own. Only 17,000 of the district’s 325,000 students are eligible for school bus rides. PiggyBack Network co-founder and CEO Ismael El-Amin displays his PiggyBack ride-hailing App in October. Charles Rex Arbogast/AP Last week, the school system launched a pilot program allowing some students attending out-of-neighborhood magnet or selective-enrollment schools to catch a bus at a nearby school’s “hub stop.” It aims to start with rides for about 1,000 students by the end of the school year.It’s not enough to make up for the lost service, said Erin Rose Schubert, a volunteer for the CPS Parents for Buses advocacy group.“The people who had the money and the privilege were able to figure out other situations like rearranging their work schedules or public transportation,” she said. “People who didn’t, some had to pull their kids out of school.”On PiggyBack Network, parents can book a ride for their student online with another parent traveling the same direction. Rides cost roughly 80 cents per mile, and the drivers are compensated with credits to use for their own kids’ rides. Takia Phillips, 15, arrives at her school in Chicago on a Friday in October after she was one of two children PiggyBack Network co-founder and CEO Ismael El-Amin helped drive to school as part of his ride-booking network.Charles Rex Arbogast/AP “It’s an opportunity for kids to not be late to school,” 15-year-old Takia Phillips said on a recent PiggyBack ride with El-Amin as the driver.The company has arranged a few hundred rides in its first year operating in Chicago, and El-Amin has been contacting drivers for possible expansion to Virginia, North Carolina and Texas. It is one of several startups that have filled the void.Unlike PiggyBack Network, which connects parents, HopSkipDrive contracts directly with school districts to assist students without reliable transportation. The company launched a decade ago in Los Angeles with three mothers trying to coordinate school carpools and now supports some 600 school districts in 13 states.Regulations keep HopSkipDrive from operating in some states, including Kentucky, where a group of Louisville students has lobbied to change that.After the district halted bus service to most traditional and magnet schools, the student group, known as The Real Young Prodigys, wrote a hip-hop song titled “Where My Bus At?” The song’s music video went viral on YouTube with lyrics such as, “I’m a good kid. I stay in class, too. Teachers want me to succeed, but I can’t get to school.”“Those bus driver shortages are not really going away,” said HopSkipDrive CEO Joanna McFarland. “This is a structural change in the industry we need to get serious about addressing.”Companies catering to kids claim to screen drivers more extensively, checking fingerprints and requiring them to have child care or parenting experience. Drivers and children are often given passwords that must match, and parents can track a child’s whereabouts in real time through the apps. PiggyBack Network co-founder and CEO Ismael El-Amin and Messiah Robinson, 6, wait outside the home of Takia Phillips as he gives the two students a ride to school.Charles Rex Arbogast/AP In Chicago, some families that have used PiggyBack said they have seen few alternatives.Concerned about the city’s rising crime rate, retired police officer Sabrina Beck never considered letting her son take the train to Whitney Young High School. Since she was driving him anyway, she volunteered through PiggyBack to also drive a freshman who had qualified for the selective-enrollment magnet school but had no way to get there.“To have the opportunity to go and then to miss it because you don’t have the transportation, that is so detrimental,” Beck said. “Options like this are extremely important.”