As thousands of hockey fans stream into downtown St. Paul this weekend, traffic — as they say — is about to get interesting.

Two major arteries into the heart of the capital city will be shut down for construction.

The disruptions will be messy; one of them will be noisy.

The first is along Interstate 35E north of downtown; the second is along Warner Road.

As part of the MnPass express lane project, I-35E will be closed Friday night in both directions for about 5 1/2 miles between I-94 and Minnesota 36 in Little Canada.

The closing will allow workers to demolish the Arlington Avenue and Wheelock Parkway bridges. The interstate is expected to reopen by 5 a.m. Monday.

“All the ramps in that stretch will be closed,” said Bobbie Dahlke, a spokeswoman for the Minnesota Department of Transportation.

“We’ll start closing ramps as soon after rush hour as we can. … That’s just to get people off the road. We’ll start closing I-35E around 9 p.m.”

Traffic will be detoured to interstates 694 and 94. The work is related to the I-35E MnPASS project, which will add a MnPASS express lane between Little Canada Road and Maryland Avenue.

Lane closures will continue nightly for several weeks in St. Paul and Maplewood as the new bridges are constructed.

The left lane in both directions of I-35E between Maryland Avenue and Highway 36 closes from 7 p.m. until 5 a.m. Mondays through Saturdays. The closures are expected to wrap up in late March.

Detours have been posted on MnDOT’s I-35E corridor project website at dot.state.mn.us.

St. Paul City Council member Amy Brendmoen, who represents the North End, said Wednesday that the proverbial light at the end of the tunnel is a better interstate and better interstate bridges.

This weekend, however, will be a “big weekend,” she said.

For hockey fans, it’s more like huge.

The Minnesota boys high school tournament is underway through Saturday at downtown’s Xcel Energy Center. On Sunday, the Minnesota Wild take on the St. Louis Blues at the X.

In addition, the St. Paul RiverCentre will host the 25th annual Let’s Play Hockey expo Friday and Saturday — the world’s largest consumer hockey trade show, featuring 350 booths showcasing hockey equipment and merchandise.

The overall I-35E project will improve the pavement along the interstate and ultimately replace the Arlington Avenue Bridge, the Wheelock Parkway Bridge, the Larpenteur Avenue Bridge and I-35E bridges on local roads.

In addition to causing headaches for travelers, residents can expect to hear pile-driving at the bridge sites from noon to 7 p.m., at the latest, on Saturday, and again from 7 a.m. to 7 p.m., at the latest, on Sunday.

The St. Paul City Council approved a noise variance for the work in February. The interstate closure had been scheduled for Feb. 28 but was delayed by heavy snowfall.

All told, improvements along the stretch of I-35E will cost about $220 million through 2015.

Meanwhile, work crews this weekend also will demolish part of the old southbound U.S. 52 Lafayette Bridge in St. Paul. That work will close Warner Road at 7 a.m. Saturday between Sibley Street and Childs Road. Weather permitting, the road will reopen by 5 p.m. Sunday.

For more information, visit mndot.gov/lafayettebridge.

Frederick Melo can be reached at 651-228-2172. Follow him at twitter.com/FrederickMelo.

ON THE WEB

For details on road closures and construction, visit dot.state.mn.us/metro/projects/35estpaul/mnpass.html.