The City of Edmonton’s Traffic Operations Branch has taken the first steps in a big leap into the future that will see the conversion of most of its traffic signals to a wireless control system.
Currently, a little more than 600 of the City’s 1,000 traffic lights are controlled via direct copper-wire links to the Traffic Management Centre at Century Place. The rest are controlled either through ethernet connection, or by stand-alone traffic cabinets on the street with an internal clock.
“The City owns some of the copper in the immediate downtown core,” says Janis Chow, traffic systems and ITS implementation specialist, “but we pay Telus for all the other lines, just as people pay for their telephone lines.”
Monthly fees charged to the city per copper line currently vary depending on distance from a telephone system switch and other factors.
“With the new wireless system, we will see a saving in monthly costs per traffic signal, since distance and wiring will no longer be factors,” says Janis.
She says the conversions are planned to begin right away, now that capital funding is in place, and to continue over the next four to six years.
She says one of the technical challenges for some of the wireless traffic signal installations will be the requirement to have a clear line-of-sight between the radio antenna at the traffic signal and the tower communicating via radio signals to the receiver.
Traffic Management Centre
Janis is in charge of the Traffic Management Centre, which is active daily from 6:30 am to 6:30 pm.
The centre’s 12-person staff maintains a real-time watch over traffic throughout the city, providing traveler information such as alerts to various incidents (like collisions) and slowdowns in traffic flow.
They’re capable of adjusting traffic signals to accommodate vehicle flow in congested areas, wirelessly posting warnings and alerts to roadside traffic information signs, and calling in field operations staff for support if there is an issue affecting traffic.
Their new traffic signal central system is so powerful – one operator calls it ‘our Ferrari’ – that it can show the current status of traffic lights at any intersection.