Vehicle engine emissions closely relate to air-ratio called lambda (λ). The current practice of examination of gasoline engine emissions is partially based on λ reading at engine idle speed. For the λ value over a specific vehicle examination standard, it indicates that a significant amount of emissions is produced. The concept of telemetry with traffic lights is proposed that allows lambda data collected from the vehicle on road to be reported in real time at a traffic light. The data can be sent via a radio transmitter in the vehicle to a radio receiver mounted on the traffic light which is connected to a PC. So, the authority can monitor the engine emission data via computer networks while the vehicles stop at red traffic lights and enforce the vehicle owners taking immediate action to fix their vehicle emission problems if necessary. © 2012 Springer Science+Business Media B.V.