Some congestion will ease while old troubles will reemerge, though exact effects are uncertain.
When the new Interstate 35W bridge opens this week, eager drivers will flock to their old routines.
Unless they're content with their new ones.
Gov. Tim Pawlenty and a host of other politicians will gather on the nearly completed bridge at 11 a.m. today to announce when the first cars will drive across, which could be as early as Tuesday. They'll also unveil details about the location and design of a memorial to the 13 people who died when the previous bridge collapsed on Aug. 1, 2007.
What the officials won't be able to announce is how the opening will affect traffic.
Congestion hot spots created by the detours should ease, said Todd Kramascz, a traffic supervisor for the Minnesota Department of Transportation. He citing the Interstate 94/694 interchange as one place where backups bloomed.
But old bottlenecks, such as 35W's junction with westbound Interstate 94, may very well return, said David Levinson, a University of Minnesota engineer who has been studying metro travel patterns after the collapse. Slowdowns also could be seen on northbound 35W where it meets Hwy. 36, he said.
The new bridge could see more cars, fewer cars or the same amount, Levinson said. "That, I think, will be an interesting thing to watch."
The old bridge saw 140,000 daily trips, Levinson said, but traffic counters saw only a 90,000 increase in river crossings on other bridges after the collapse, meaning that drivers either switched their destinations or canceled trips altogether.
And because gas prices are high, "total travel is down a little bit this year from last year," Levinson said. "That might offset some of the increase that you'll see on particular routes."
Individual lives have changed as well over the past 13 months. Ben Edwards of Arden Hills used to take the old bridge every day on his way to Eden Prairie, but since April he's been working in northeast Minneapolis.
He figures the bridge opening will reduce the backups he encounters at the exit to SE. 4th Street. "Even if I don't cross it, it will help me," he said.
Levinson said that after the collapse, it took about 10 weeks for drivers around the metro area to settle into a consistent travel pattern. He expects a similar but shorter period of trial and error to take place when the new bridge opens.
"It will take some time to shake out," he said.
Some drivers may wait to cross the new bridge because they're wary of how fast it was built, but Edwards is not among them.
"If I could be the first to cross it, I would," he said. "There's been plenty of traffic on it already with the construction crews. ... It's probably the safest bridge in the country right now."
Jim Foti • 612-673-4491