Traffic patterns are changing on a major Miami causeway. What it means for your drive

Heading to downtown Miami from South Beach? Pay attention — because your exit might not be where it used to be.

Starting Wednesday morning, July 31, the MacArthur Causeway exit to Biscayne Boulevard will be moved a quarter of a mile east, closer to Watson Island, according to the Florida Department of Transportation. The existing exit-only lane that leads to downtown will be blocked off by a concrete barrier.

The change also will affect the MacArthur bike-lane, and require cyclists to detour off the causeway.

The new traffic pattern is part of the ongoing “Connecting Miami” construction project, anchored by a signature bridge downtown, with work affecting parts of I-395, I-95 and State Road 836.

What does the downtown Miami exit change mean for your commute? Here’s what to know:

What is the new traffic pattern?

Construction crews on the MacArthur Causeway, State Road 395, are moving the right-side exit lane a quarter-mile east “to make more room for construction activities,” said Oscar Gonzalez, a representative for the Florida Department of Transportation.

So, driver’s heading west on the causeway who want to use Exit 2 toward Biscayne Boulevard “will now have to exit one quarter of a mile earlier, which means by the time they’re exiting Watson Island, they should already be at the rightmost lane,” Gonzalez said.

Will the new pattern cause delays?

Drivers should expect delays due to the pattern change.

“Whenever we make any changes to traffic patterns,” said Gonzalez, “there’s always a period where folks need to get accustomed.”

FDOT will put up electronic message boards, update signs and add pavement markings to limit delays and make the new exit and traffic pattern as clear as possible.

How will the MacArthur Causeway bike lane be affected?

The bike-lane along the causeway will be closed during this phase of construction.

Bicyclists will have to detour off the causeway and onto the Parrot Jungle Trail bike route, before returning to the causeway lane after the construction area.

Is the causeway traffic change permanent?

The upcoming changes to the causeway exit location aren’t permanent. But the change will be in place for about two years, Gonzalez said.

Why is the downtown Miami exit moving?

The new traffic pattern will make more room for construction on the ongoing “Connecting Miami” project that is reshaping major roadways in downtown Miami.

The project is more than just enhancements to major highways downtown, but involves the creation of a new signature bridge along I-395 that will become part of the Miami skyline.

The construction project, which was started five years ago, is projected to cost $840 million, with expected completion in 2027.