Background: The reconstruction of the I-480 / US-75 Interchange is the final segment of the interstate reconstruction in the City of Omaha and was included as part of the Environmental Assessment written for the I-80 reconstruction.
The need for the project and project schedule is controlled by the existing bridge conditions. The interchange bridges need to be replaced or need to be repaired to maintain them safely for the public. The interchange was originally built to connect a West Expressway in the Dodge Street corridor. The expressway was never built, which left the interchange with several unused bridges and substandard connections to the city streets. Since the interchange was constructed, design standards have also changed. The existing interchange incorporates several left side ramp entrances and insufficient sight distance, given current traveling speeds.
The project will improve traffic operations with extended ramp merges, added auxiliary lanes and flatter road profiles to improve sight distance.
Proposed Construction: The project limits are from Harney Street on the south to Hamilton Street on the north, and from 30th Street on the west to 20th Street on the east. A section of 30th Street will also be rebuilt. The Project will include removal of seven existing bridges, the construction of thirteen new bridges, concrete pavement, grading, culverts, lighting and guardrail.
Ramp access to and from the local street system will remain basically the same with the following exceptions:
NOISE: Areas of this project have been identified as having noise levels that approach or exceed the Leq Noise Abatement Criteria (NAC) of 67 dBA for receptors listed in Activity Category B(residential) and 72 dBA for receptors listed in Activity Category C(commercial/industrial). As a result, thirteen separate areas were analyzed for noise abatement, however none of the thirteen areas meet the federal/state requirements for feasibility and reasonableness. Therefore no noise abatement measures will be included in the project.
Lighting/Signal/Signage: Eighteen new overhead sign structures will be erected. The Signage Plan is available.
Traffic Flow/Phasing:. Reconstruction will be accomplished through 16 individual projects.That will allow the work to be phased in an effort to maintain traffic. Although through traffic will be maintained, certain entrance ramps may be closed temporarily to facilitate construction.
Right-of-Way: There are no ROW plans at this time.
Schedule: The interchange is planned to be reconstructed over a 3 to 4 year period beginning in the fall of 2005. Construction info for 2006-2008 is listed above.
Estimated Cost: The total cost of the entire interchange reconstruction is estimated at $41 Million.