State transportation officials said Thursday that congestion on Twin Cities roadways ticked up slightly in 2009, after falling noticeably in 2008.
The state's Metropolitan Freeway Congestion Report says that 18.2 percent of Twin Cities freeways were congested. That's up from 17.3 percent the year before.
MnDot tracks traffic using detectors embedded in roads. They have about 4,000 of them around the Twin Cities, and they can track vehicle speeds. When cars and trucks fall below 45 mph for more than a few minutes, officials consider the road congested.
Freeway engineer Brian Kary said the annual report is used to help guide decisions by state transportation officials.
"We use it for a number of different things, in terms of trying to expand our freeway management system, our detector systems, our cameras, our signs out on the freeway," Kary said. "But then we also use it for long-term planning, for project development, as well as where to add transit service, like BRT, or bus rapid transit."
Kary said there's been kind of a general trend upward and thinks we're into a more typical year. "We didn't have any major construction projects coming on line this year," he said. "[So] it could be a sign of changes to the economy, but it's a little hard to decipher exactly what it is."
There are about 400 miles of freeway in the Twin Cities monitored by MnDOT.