In an effort to improve pedestrian safety, Toronto is converting all its pedestrian traffic lights so they have “countdown signals” indicating how much long­er it will be before the light turns. The Toronto Star asked Bruce Zvaniga, manager of the city’s urban traffic control sys­tems, about the signals.

Q How many pedestrian signals are there in the city?
A 2,160.

Q How many have been converted to count-down mode?
A 2,100. Most of those that haven’t yet been converted need special handling — such as lights near fire stations that are set to give fire trucks an automatic green light. That can interfere with the countdown. All should be converted this year.

Q How long is the interval between numbers?
A One second. If the countdown starts at 10, you have 10 seconds to cross.

Q How long does the white pedestrian silhouette last?
A Seven seconds.

Q What determines the length of the signal?
A The distance across the street.

Q How much time does the signal give pedestrians?
A When the countdown starts, it assumes pedestrians will walk 1.2 metres per second to get to the other side. That’s 4.3 km/h. If you include the seven-second period with the white light, pedestrians must walk about one metre per second, or 3.6 km/h, to cross in time at an average street.

Q Who determines the timing?
A The signals are set using standards agreed on by most North American traffic engineers. It’s also contained in the Ontario Traffic Manual, published by the province.

Q Should pedestrians be given more time?
A It’s an ongoing argument. Giving pedestrians more time to cross means longer wait times for traffic — and pedestrians wanting to cross in the other direction. That can induce impatient pedestrians to cross against the lights. It can also hold up transit vehicles and other traffic waiting for lights.

Q Have the count-down signals led to fewer accidents and fewer deaths?
A Statistical information is still being gathered.