A friend tells me that all traffic lights in the city are operated by underground sensors

Most of the city’s traffic lights don’t rely on underground sensors. Lights are allotted set intervals—say, 36 seconds for green, four seconds for amber and 30 seconds for red—timed to adapt to rush-hour traffic. A different mechanism is in place at bustling intersections where residential side streets meet big thoroughfares (such as at Crescent Road and Yonge in Rosedale). Drivers on main streets are graced with a continuous green until someone wheels over a side street’s sensor (or pushes the walk signal button). But the fanciest system is situated along Lake Shore Boulevard between Windermere Avenue and Leslie Street. Here, sensors monitor traffic flow, fine-tuning the lights’ timing for maximum efficiency. And you thought hitting a slew of greens was just dumb luck.