A key downtown Miami street is about to close forever. Are you ready for it?

Will Miami traffic ever get better? Not until it gets worse.

For now, get ready for a major highway construction project that will shut down a key artery for downtown Miami drivers.

The Florida Department of Transportation and the Miami-Dade Expressway Authority are permanently closing Northeast 12th Street from Biscayne Boulevard to Northeast First Avenue. The shutdown on Aug. 12 is for the construction of a new “signature bridge” and other work along Interstate 395.

Expect some pain and confusion in and out of downtown.

In addition to the street shutdown, the five-year, $802 million ”Connecting Miami” reconstruction project of I-395 — double-decking a section of the highway, repaving a stretch of I-95 and building a spider-like bridge over Biscayne Boulevard — will mean lane closures, traffic shifts and detours.

Rendering of the planned “signature bridge” over Biscayne Boulevard in downtown Miami, part of the reconstruction and redesign of I-395. Connecting Miami

The closure of Northeast 12th Street will not happen all at once. It will be completed in two steps.

Starting Aug. 5, this coming Monday, the Northeast 12th Street ramp to westbound I-395 and I-95 will be permanently closed. Drivers on 12th Street wanting to access westbound I-395 and I-95 can continue west on 12th, only the side ramp will be closed.

step one of closures.png
As the first step of the closure of NE 12 Street, on Aug. 5 the NE 12 Street slip ramp to westbound I-395 and I-95 will be permanently closed. FDOT/MDX

Step two goes into effect Aug. 12. . Northeast 12th Street will be permanently closed from Biscayne Boulevard to Northeast First Avenue.

Drivers on southbound Biscayne Boulevard or Northeast Second Avenue wanting to access westbound I-395 or I-95 can turn right on 13th Street, then turn left on First Avenue to access the westbound I-395 ramp. Northeast 1st Avenue will be converted to a two-way street from 13th Street to I-395 to accommodate the traffic.

step two of closures.png
Step two goes into effect August 12. Northeast 12 Street will be permanently closed from Biscayne Boulevard to Northeast 1 Avenue. FDOT/MDX

The schedule of these changes may change due to bad weather.

Traffic officials expect drivers to have some trouble navigating the new routes.

“Whenever a new traffic pattern is initiated it typically takes about a week or two for drivers to become accustomed to the new pattern,” said Oscar Gonzalez III, senior community outreach specialist for the Connecting Miami project, in an email.

There will be several portable message signs before the new traffic pattern starts to inform drivers, Gonzalez said. Once the new pattern goes into effect, the signs will be changed to give directions for the new routes.

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Miami Herald Real Time Reporter Devoun Cetoute covers breaking news, Florida theme parks and general assignment. He attends the University of Florida and grew up in Miami. Theme parks are on his mind in and out of the office.