Things are a bit out of sync on the streets of Minneapolis.

A power failure on Sunday threw off the coordinated timing of many traffic signals sprinkled throughout Minneapolis, frustrating motorists and extending commutes throughout the week. The inconvenience could last for several more days, according to Minneapolis traffic and parking services director Jon Wertjes.

In comments posted online, exasperated motorists complained their commuting times had doubled. "Highway 55 from 100 to 94 (going east) was a mess this morning," stated one post. "One of the traffic lights would go to green for less than a minute while the others would stay green much longer. What a mess."

Stuck in a line of traffic at Washington and 11th Av. S., Megan Hauglie was driven to sarcasm when asked about the un-timed lights. "It's been really awesome," she said.

The power failure struck the signals' central computer system, which operates about 700 of the city's 800 controlled intersections. Busy Hiawatha Avenue's signals operate independently of this system and are unaffected.

The hiccup prompted "a number of calls" from the public about the behavior of the signals, Wertjes wrote in a letter Thursday to the city's leadership.

A backup system took over, allowing traffic signals to follow the standard "green, yellow, red" sequence.

Typically, the system optimizes traffic flow by coordinating signals at intersections along a street to keep vehicles moving.

But with the lights thrown off their timing, "It's been really bad today," said a traffic cop at the intersection of Washington and 11th Avenues S.

Until the repairs are completed, the public will continue to experience increased traffic delays and congestion, Wertjes said in his letter. In the meantime, drivers who see "significant traffic signal timing" problems should call 311 and report them.

The power failure involved a surge of electricity that crippled an Xcel Energy transformer, Wertjes said in his letter.

The city hopes to have a new computerized signal system that would prevent such problems in place by 2013, Wertjes wrote.

He said motorists who typically roll along a particular thoroughfare might end up hitting four to five red lights, when the norm had been two or three.

"There are hot spots we're trying to address" by going out to specific intersections and making adjustments to improve things for drivers, he said. "Normally, we can sit in the office and make the changes."

The lights are timed not only for traffic flow, he said, but to reduce exhaust emissions from vehicles sitting at red lights and "it's better for safety, too."

He identified some areas of particular impact as 5th Avenue S. where northbound Interstate 35W pours into downtown, along Central Avenue leaving downtown and "the Hennepin/Lyndale bottleneck by the Walker [Art Center]."

Some drivers who posted online comments, however, used the power outage to register their discontent with the overall Minneapolis traffic system. "We have a system in place to coordinate lights? Are you kidding me," wrote one driver. "I would never have guessed with all the red light gridlock we have to endure."

Said another: "Maybe I like the uncoordinated lights. Didn't have to drive 40 to hit the light from 10th to 9th....SIGH I suppose Mpls will 'fix' this and then I will have to speed again to make the light one block away. Brilliant."

Staff Writer Matt McKinney contributed to this report. • 612-673-4482 • 612-673-4788