Semaforul (din fr. sémaphore) este un dispozitiv de semnalizare optică, ce indică diferite semnale referitoare la circulația rutieră, feroviară, maritimă etc.
- Semafor la dexonline
- FHWA Arterial Management Website, latest information on traffic signal operations
- Traffic Lights by Ed Pegg, Jr., Wolfram Demonstrations Project: demonstrates that there are "seven distinct light cycles that will prevent collisions."
- Animations of various US signal phasings
- Micro Controller based Traffic Light Controller.
- SCATS – Sydney Coordinated Adaptive Traffic System
- InSync: The #1 Self-Optimizing Traffic Signal System. Pioneer in Artificial Intelligence and Robotics for Traffic Signal Optimization
- Safety Evaluation of Converting Traffic Signals from Incandescent to Light-emitting Diodes: Summary Report Federal Highway Administration
- Safety Evaluation of Discontinuing Late-night Flash Operations at Signalized Intersections: Summary Report Federal Highway Administration
- Traffic signals, 1922, digitized NYPD photograph from the Lloyd Sealy Library Digital Collections