An occasional update on items from Motordom – the world of auto dominance
IS SYNCHRONIZING TRAFFIC SIGNALS A GOOD IDEA?
Yes, say some.
Minneapolis is in the midst of an upgrade for its traffic-control system that includes a new computerized system that can re-time traffic signals to make traffic flow more efficiently.
New signal timing is in place downtown; changes in the rest of the city will be complete by next summer. The $11.2 million project is funded by a federal grant and state, county and city money.
City officials say traffic flow downtown could improve by 10 percent. The system also allows the city’s Traffic Management Center to analyze traffic patterns and activate and turn off left-turn arrows.
No, say others:
“Any time you make it easier or faster or less congested on a road, the more people will drive,” says Dom Nozzi, a transportation consultant based in Boulder, Colo., who blogs at nozziwalkablestreets.com.
“When we introduce changes that make it less inconvenient or less congested, we induce new car trips that would otherwise not have happened,” he says.
It depends, say Reid Ewing:
It’s difficult, though, to get it right, he says:
Too often, Ewing says, protected left-turn arrows slow the entire system.
Cross streets can be given too much time on green lights, slowing traffic on major roads that intersect with them.
Traffic engineers don’t always update signal intervals to match changes in volume and flow.
To work correctly, signals must be close to each other or at least a quarter-mile apart. The progression of traffic through irregularly spaced synchronized signals isn’t optimal.