YardSafe
Blue-flag enforcement system for rail yards, deployed to carriers including NJ TRANSIT and MARTA. Tech lead at Bombardier Technology Solutions. Smart Rail USA Product of the Year, 2015.
What it is
A blue-flag enforcement system for rail yards. YardSafe is an engineered safety solution that provides location awareness for workers inside rail yards and maintenance facilities, and integrates with yard equipment so that the rule — “do not move this car; there are workers under it” — is enforced as a technology state, not a procedural intent.
I was the technical lead on YardSafe. The system shipped to passenger-carrier clients including NJ TRANSIT and MARTA. In 2015 it was named Product of the Year at the Smart Rail USA Innovation Awards.
Why blue flags
The blue flag is the oldest safety device in North American rail: a blue signal on a track means workers are under or between the equipment, and the equipment must not be moved. The rule is absolute. Enforcement has historically been procedural — the rule describes what must happen; the humans in the yard are trusted to honor it.
YardSafe made enforcement technical. Location awareness of workers, combined with interlocks against yard equipment movement, means the blue-flag rule is honored by the system whether or not anyone sees the flag. The rule itself did not change. What changed is that it is no longer possible for a dispatcher, a switcher, or a conductor to violate it by accident.
What it taught
Enforcement of an absolute rule at the technology layer is the same class of problem as the regex cascade in StrongAfter: deterministic overrides that run before judgment enters the loop. The rule is: workers present → equipment does not move. That rule runs before anyone’s attention, opinion, or fatigue gets a vote. The lesson — that absolute rules deserve absolute enforcement, not exhortation — carried directly into how I architect AI safety boundaries now.
Awards
- Product of the Year, Smart Rail USA Innovation Awards, 2015