The long-awaited rebuilding of Hwy. 100 is causing major headaches in St. Louis Park.

Traffic backups of nearly two-thirds of a mile have been reported on Lake Street since the Minnetonka Boulevard bridge closed about 10 days ago. Other major streets, including Wooddale Avenue, are backed up every day for the entire afternoon, city officials say. Motorists seeking to avoid traffic jams are speeding through neighborhoods, and there are concerns about emergency vehicles being able to get through the congestion.

Worst of all, the city says, MnDOT staff working on the Hwy. 100 project have failed to address the problems.

In a sternly worded letter this week sent to nine department officials — including Commissioner Charlie Zelle — St. Louis Park City Manager Tom Harmening cited “serious traffic and safety issues” and demanded immediate action from MnDOT.

“Given our inability thus far to gain support from MnDOT project staff to adequately address these concerns, I felt I had no alternative but to contact you for help,” Harmening wrote. In an interview Wednesday, Harmening said the city has been “inundated” with phone calls, e-mails and social media posts from residents.

“We’ve gotten hundreds and hundreds of contacts,” Harmening said. “What I want to be sure our residents and business owners understand is, we’ve been talking to MnDOT extensively to take some measures to alleviate these concerns.

“Thus far, we’ve been told [by project managers] that they’re just not going to do it,” he said. “Given that, we didn’t have much choice but to engage in a dialogue with someone at a higher level of authority.

“We just think it’s a tragedy waiting to happen,” Harmening said. “We’re just trying to head that off.”

A MnDOT spokeswoman said the department has been monitoring the situation and will have a response to the city’s letter on Thursday. But it’s too soon to say exactly what measures will be most effective in dealing with the traffic disruption caused by the project, said MnDOT spokeswoman Bobbi Dahlke.

“We share their concerns. We hear them. Safety is an issue for us as well,” she said. “We want all the same things they do.” But the city’s proposed solution — installing temporary traffic signals at several key intersections and ramps — isn’t necessarily the best one, she said.

“We have studies showing that signals at that intersection will be ineffective,” Dahlke said. “There are other ways to manage traffic. We want to make sure we understand what the needs are and put measures in place that will keep everyone safe. We’re in the very early stages of this.”

The $60 million project will reconstruct Hwy. 100 at the Hwy. 7 and Minnetonka Boulevard interchanges and widen the road to three lanes in each direction. Sue Sanger, a St. Louis Park City Council member, said the city is happy the project is moving forward, but has been frustrated that more wasn’t done in advance to deal with the disruption that everyone knew would be coming.

“MnDOT staff has been very reasonable in many other ways,” Sanger said. “But this problem needs higher-level attention.”