4th St NW bridge over I-90 in Austin opens to traffic, three of four ramps open
AUSTIN, Minn. – Motorists can again cross over Interstate 90 at 4th Street Northwest in Austin as crews opened the newly constructed bridge this afternoon (Nov. 21, 2025), according to the Minnesota Department of Transportation.
The bridge opened to traffic along with three of the four I-90 ramps. Both eastbound I-90 ramps are open along with the westbound I-90 on-ramp.
The westbound I-90 off-ramp remains closed because the work zone for the ongoing construction of the westbound I-90 Cedar River bridge is at the off-ramp. Work continues on the river bridge and will be completed in 2026. The westbound I-90 on-ramp at 6th Street Northeast is also closed because of this work zone, but the westbound off-ramp remains open.
Detours for westbound I-90 traffic wanting to exit at 4th Street Northwest are to travel west to 14th Street Northwest. Detours for traffic wanting to get on westbound I-90 at 6th Street Northeast are to travel east on I-90 to 11th Drive Northeast, cross I-90 and return to westbound I-90 using the on-ramp.
To learn more about the project, visit the MnDOT project website where you can also sign up to receive email and text message updates. This is Year 2 of a three-year $50 million construction project at six sites in Austin. Other bridge construction is planned for 2026.
Single-point urban interchange
The new design of the bridge is called a single-point urban interchange because the primary signals are on a monotube in the middle. It's a change for motorists, but directions can be determined by looking at the signs, following the traffic signals and pavement markings.
Plan to go slow as you learn this area just as you would a new roundabout or other change in traffic.
To drive through a single-point urban interchange in Minnesota, follow the signs and lane markings. All traffic movements are controlled by a single set of traffic signals in the center of the intersection.
Right turns are permitted in any phase, while left turns and through traffic are controlled by three phases: one for through traffic, one for left turns leaving the interstate, and one for left turns entering the interstate.
Remember to allow extra space for larger vehicles, as single point urban interchanges are designed with larger, more gradual turns.
Navigating a single-point urban interchange
- Follow the signs and lane markings: The key difference is that one central traffic signal controls all left turns and through traffic. Pay close attention to signs and pavement markings to get into the correct lane for your movement.
- Right turns: You can make a right turn at any time when it is safe, as right turns do not interfere with the main signal phases.
- Left turns: Left turns are phased at the central signal:
- Phase 1: Through traffic on the main arterial road.
- Phase 2: Vehicles turning left to exit the interstate.
- Phase 3: Vehicles turning left to enter the interstate.
- Go straight: You can proceed through the intersection like a traditional one, but you must do so within the signal phases indicated for through traffic.
- Be aware of larger vehicles: These interchanges are designed to accommodate large vehicles like trucks and buses with wide, gradual turns. Ensure you are giving them ample space, especially when turning.
What's next
Crews are working to complete the westbound I-90 bridge at the Cedar River, which will be completed in 2026. Additionally, these projects are planned for completion in 2026:
- 14th Street/Highway 218 North
- The two bridges at this location will be replaced by one bridge and roundabouts will be constructed at each ramp intersection with 14th Street The southbound bridge will stay open to two-way, single-lane traffic to the extent possible during construction. Detours will be provided at 4th Street. View the proposed design.
- 21st Street /Highway 218 South
- The 21st Street bridge and the south ramps will be reconstructed. The new bridge crossing will provide a wide walkway and connections to local trails. 21st Street will be closed during construction. 11th Drive and 28th Street will be available for short detours. View the proposed design.
Stay connected, informed
- Check out upcoming MnDOT southeast Minnesota construction projects.
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