Three high school seniors built a pedestrian-safety app in 24 hours, and families at Freedom Hill Elementary can use it to find safer walking routes to school.

SafeWalkr launched Wednesday, Oct. 7, as a pilot at 14 Fairfax County Public Schools (FCPS). Three Thomas Jefferson High School for Science and Technology (TJHSST) seniors built the free web app: Daniil Prokofev, Ashwath Muppa and Isaac Leetyn. The launch coincides with National Walk and Roll to School Day.

Freedom Hill Elementary on Lord Fairfax Road is the only Vienna school on the pilot list.

The app scores walking routes on a 1-to-10 risk scale. It uses Google Street View imagery, county traffic records and sidewalk data to steer students away from high-speed roads and onto paths with crosswalks and continuous sidewalks. According to the app's website, the safest route is not the shortest for two-thirds of homes it covers.

Prokofev said the idea came from a run home from school in which Google Maps directed him along Braddock Road with no sidewalks. "I was fighting through shrubbery; it was getting dark, and there were so many cars in close proximity to me," he said in an FCPS article about the project.

The trio built the first version overnight at HackTJ, TJHSST's annual coding competition, drawing on skills from a machine learning class taught by teacher Nicole Kim. The project won the event.

TJHSST principal Mike Mukai visited the team around 11 p.m. during the hackathon and connected them with Becky Gray, a Safe Routes to School specialist in the FCPS Office of Safety and Security. Gray helped the students refine the app for local families. The team also consulted FCPS Chief Technology Officer Gautam Sethi on cybersecurity standards and Chief Safety and Security Officer Brian Lambert on safety protocols.

The launch follows a series of pedestrian incidents in Fairfax County. On Sept. 8, three FCPS students were hit by vehicles while riding bicycles or scooters in separate incidents on a single day. One middle school student died. Superintendent Michelle Reid issued a division-wide safety message in response. The Board of Supervisors later approved funding to restore high school crossing guards that had been cut at the start of the school year, according to FFXnow on X.

The 14 pilot schools were chosen based on a traffic and pedestrian survey conducted during the 2025-2026 school year. Besides Freedom Hill, the list includes nine other elementary schools, two middle schools and two secondary or high schools. Math teacher Sewon Yang, the team's project adviser, is credited with securing funding support for the app.

SafeWalkr is free at safewalkr.com. FCPS has not announced how long the pilot will run or what would trigger a broader rollout.