This design-build project is building a barrier separating northbound I-75 travel lanes from traffic entering and exiting the interstate between the SR 574 (Dr. Martin Luther King Jr. Boulevard) and I-4 exits ramps in Hillsborough County.

A two-lane northbound collector-distributor (CD) roadway is being built east of the current northbound travel lanes within the existing right of way. Traffic entering and exiting northbound I-75 at SR 574 (Dr. Martin Luther King Jr. Boulevard) and I-4 will use the new CD roadway.

In addition, the SR 574 (Dr. Martin Luther King Blvd) interchange will be converted to a diverging diamond interchange. 

These changes will improve the efficiency and safety of the interstate in this area.

Construction activities are expected to finish during summer of 2025. 

What is a DDI?

A Diverging Diamond Interchange (DDI) is an innovative, modern interchange design that can relieve traffic congestion and improve safety for drivers, bicyclists and pedestrians. In a DDI, traffic crosses to the left side of the roadway allowing for ease of access to the interstate by eliminating difficult left turns. With traffic diverted to the left side of the roadway, vehicles making a left onto the interstate entrance ramps do not have to cross oncoming traffic, creating fewer conflict points. The reduction of conflict points eliminates potential user collisions, thus improves safety and vehicle throughput.

How does the DDI work?
Unlike a conventional diamond interchange, no matter what direction you are driving, you diverge, or cross to the left side of the road through the interchange, and then cross back over to the right side of the road, on the opposite side of the interchange. The Diverging Diamond Interchange reduces vehicle delays by allowing traffic to enter the interstate without waiting at a left turn signal.  To do this, traffic is redirected from the right side of the bridge to the left side.

• This design allows for more efficient signal timing, which reduces delay times and minimizes conflict points
• Enables the interchange to effectively handle higher volumes of traffic

• Increased safety and capacity while reducing vehicle delays and crashes
• Ability to handle heavy left turn volumes
• Increased safety for pedestrians and bicycles

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*Construction cost includes original construction contract amount plus approved contract changes. It does not include inspection oversite.