December 20, 2017 – In 2015, Interstate 80 carried 46,700 vehicles per day in the Quad Cities Area. This is an increase of 32% from 2002. In addition, truck traffic is increasing in the Quad Cities at a greater rate than many other portions of the state at 37%. Local representatives believe 6-laning of I-80 would allow for merging and weaving movements at interchanges. Because of these issues and others, the Iowa Department of Transportation conducted an Interstate 80 System Study. The need for this study was identified in the last two Quad Cities long range transportation plans. The study included an analysis of geometry, physical condition, traffic operation, and safety. The study has found that:
- 21 of 28 ramps are rated poor in safety due to crashes
- Crash rates are expected to increase
- The right shoulder of I-80 is rated poor throughout the Quad Cities
- Reconstruction would eliminate left hand exits that don’t meet current interstate design standards
A separate study was also conducted by both Illinois and Iowa DOTs for the I-80 Bridge over the Mississippi River. The I-80 Bridge study compared reconstruction to full replacement of the structure and determined full replacement was the preferred alternative, widening to six lanes. Both DOTs are now preparing to conduct a Planning and Environmental Linkages Study for the I-80 Bridge.
Iowa DOT staff and Federal Highway Administration worked with City of Bettendorf staff to complete the Middle Road Interchange Justification Report (IJR). An IJR or an Interchange Operations Report (IOR) is required for major improvement projects on interstate interchanges, and only I-80 at Middle Road has a completed report. Also, the City of Bettendorf purchased the right-of-way for the eastbound ramp of the Middle Road interchange. The interchange in 2015 had nearly 36,000 entering vehicles, and with recent development, these numbers are even higher today. Plus, 67% growth of traffic is expected in the future. The interchange has not been updated since its construction, and it does not meet current design standards with inadequate merging lanes on a narrow bridge overpass.
The interchange at I-74 and I-80 also needs improvement with over 63,000 entering vehicles and 39% growth expected in the future. Three of four ramps at this interchange are rated poor for crashes, and the east and westbound I-74 bridges over I-80 are rated poor for width. The I-80 Study recommended a flyover from westbound I-80 to southbound I-74.
The I-80 and U.S. 61 interchange in Davenport is very congested. There are over 78,000 entering vehicles per day with 28% growth in traffic expected. The merging lanes onto I-80 are inadequate, contributing to 232 average crashes. All of the ramps at this interchange are rated poor for geometry.
The I-80 and Northwest Boulevard interchange in Davenport has over 51,000 entering vehicles per day with 23% future growth in traffic expected. Three of four ramps at this interchange are rated poor for geometry, compounded by high truck volumes. The I-80 Study recommended reconfiguration of this interchange due to existing and projected truck volumes. The Eastern Iowa Industrial Park off of this interchange is attracting industry at this location including Sterilite and Kraft.
The interchange at I-80 and I-280 has over 58,000 entering vehicles with 70% growth in future traffic expected. The north and westbound bridges at this interchange are rated poor for width. In 2008, the City of Davenport worked with Iowa DOT on an analysis of the alignment of the Kimberly Road at I-280 interchange. The interchange is less than a half mile from the I-280 at I-80 interchange. Current safety standards require at least a one-mile separation between interchanges.
With all of the needs, the Iowa DOT has committed to conducting a Planning and Environmental Linkages Study for the Interstate 80 mainline. This study will identify improvement priorities prepare for future environmental requirements.