1st Avenue Improvements
1st Avenue Improvements: 6th Street to 9th Street
1st Avenue between 6th Street and 9th Street is undergoing total reconstruction in 2018. This is the final section of 1st Avenue that needs to be improved south of Interstate 80.
After work is complete, this stretch of 1st Avenue will feature:
- Four through lanes and one continuous center turn lane
- 10 foot wide sidewalks on both sides
- Upgraded traffic signals at E. 7th Street
- New traffic signals at 6th Street with a new four-leg intersection at 1st Avenue and 6th Street to accommodate a future connection of E. 2nd Avenue on the east leg
- New public utilities (storm sewer, sanitary sewer, and water main)
- Bid in January 2018 IDOT letting
- Low bid: $7,186,554.84 (Langman Construction of Rock Island, Illinois)
- Funding: $5.1 million of Surface Transportation Program funds, and local funds
- Start: March 2018
- Estimated completion: December 2018, weather permitting (driving lanes, sidewalks, and traffic signals)
- Landscaping and final work: Spring 2019, weather permitting
- There are traffic delays
- Single lane traffic in both directions along 1st Avenue is maintained
- Pedestrian access is maintained using temporary surfacing and channelizing barriers
- Access to all businesses is maintained
- 6th Street is closed between 1st Avenue and the Baymont Suites driveway from approximately late April until late July
- The temporary traffic signals at the 1st Avenue/E. 7th Street intersection will be removed in late winter/early spring 2018 while E. 7th Street is closed and reconstructed
- Temporary traffic signals will be installed in the summer of 2018 at the new 1st Avenue/6th Street/E. 2nd Avenue intersection during construction. This signal will provide construction access to the new E. 2nd Avenue for the Iowa Arena/UIHC Phase 2 Clinic Projects.
Public Transit Impact
- Coralville Transit riders may experience delays on all routes, especially during peak traffic times. Any changes to routes and schedules will be posted on www.coralville.org/transit.
ResourcesMaps & Documents
- Project map and construction phases (PDF)
- Phase 2 - Stages 1 and 2 (PDF)
- 1st Avenue project schedule (PDF)
- "1st Avenue Update: June 12"
- "1st Avenue Update: Traffic Shifts June 4"
- "1st Avenue Update: Week of May 14"
- "Next Phase of 1st Avenue Construction Begins April 24"
- "1st Avenue Update: Week of April 16"
- "1st Avenue Update: Week of April 9"
- "1st Avenue Update: Week of April 2"
- "1st Avenue Update: Week of March 26"
- "1st Avenue Road Reconstruction: The Basics" (March 20, 2018)
- More videos available in the future
Weekly job meetings are Thursdays at 9:00 am at City Hall, until further notice. The public is welcome to attend and participate.
Lane Closures/Traffic Changes
- 1st Avenue traffic is reduced to one lane in both directions the entire length of the project, from 6th Street to 9th Street (see Resources: "Phase 2 - Stages 1 and 2").
- 6th Street west of 1st Avenue is closed between 1st Avenue and the Baymont Inn & Suites driveway (see Phase 2 – Stage 1 in Resources: "Project map and construction phases"). Information about impacted Coralville Transit routes and stops is available at www.coralville.org/transit.
- The inner left turn lane on eastbound 5th Street approaching 1st Avenue is closed until further notice to simplify the merging of 5th Street traffic turning left onto northbound 1st Avenue.
Current & Upcoming Work*
Work completed the week of June 18:
- Most of the new 12” diameter water main is installed along the west side of 1st Avenue within the combined Phase 2 – Stages 1 & 2. There are several connections to make before the new main can be tested for bacteria and leaks and then put into service.
- Final preparation of the pavement subbase south of the railroad crossing is delayed due to recent rainfall.
- Electrical conduit installation for traffic signals and lighting continues at the 6th Street intersection.
- The northeast corner radius of 1st Avenue and E. 7th Street (currently backfilled with gravel, but rutting) will be paved on June 22 with temporary concrete.
- Complete connections between new segments of 12” diameter water main and begin testing the new main. Testing involves flushing out the new main, disinfecting it with chlorine, then testing for bacteria. If the bacteria test passes, the main is flushed out, filled with water, then pressurized to check for leaks (the actual testing procedure is more involved; this is a simplified description).
- After water main testing is complete, begin connecting business water services to the new main.
- Continue 10” diameter sanitary sewer installation moving north from Pipeline Road. While the new water main is 5’ to 10’ deep, the new sanitary sewer will be 12’ to 17’ deep. Not an easy task for the contractor given the constrained corridor!
- As the sanitary sewer work continues north, a second crew will follow behind with new storm sewer (24” & 30” diameter) along the westerly curb line, between the water main and sanitary sewer.
- Complete electrical conduit installation at the 6th Street intersection.
- Identify and repair areas of soft subgrade at 1st Avenue & 6th Street that could result from recent rainfall, then finish placing subbase south of the railroad crossing and begin pouring concrete mid-to-late week, likely starting with 6th Street.
- Week of June 25, begin pouring new concrete pavement within Phase 2 – Stage 1 south of the railroad crossing.
- Phase 2 – Stage 1 is scheduled for completion on July 25 (this will reopen the connection from 6th Street to 1st Avenue).
- The initial work within Phase 2 – Stage 2 will extend water main, sanitary sewer, and storm sewer along the west half 1st Avenue, generally working from south to north. This utility work is scheduled for completion in mid-July.
- Phase 2 – Stage 2 is scheduled for completion in late August (this completes the entire west half of 1st Avenue).
How to Merge Efficiently on 1st Avenue
When traffic is slow and heavy, merging too early can create traffic backups. During peak traffic times on 1st Avenue, using a "zipper merge" can keep traffic moving and reduce traffic backups.
A "zipper merge" is when drivers use both lanes of traffic until they reach the defined merge area, and then alternate in "zipper" style into the open lane. This maximizes road space, reduces congestion, and allows both lanes to move at similar speeds.
How to "Zipper Merge"
- Watch for signs giving drivers notice that there is a merge ahead
- Stay in your lane up to the point of merge
- Take turns with drivers to safely ease into the remaining lane
- Always merge when it is safe
When is it best to use the zipper merge?
When traffic is congested and traveling at slower speeds, it is best to remain in your lane until the point where traffic can take turns merging, which is indicated by a "BEGIN MERGE" sign.
When is it best to merge early?
When traffic conditions are light and vehicles are traveling at highway speeds, it is best to merge as soon as safely possible.
Zipper Merge Resources
How We're Keeping Traffic Moving
To reduce traffic delays during construction:
- Staff will monitor traffic times and adjust the timing of traffic signals as needed to help the traffic flow on 1st Avenue
- Installed fiber optic communications at the 1st Avenue/E. 9th Street traffic signal
- Installed pan/tilt/zoom cameras on 1st Avenue at both 5th Street and E. 9th Street, along with existing cameras at 1st Avenue/Highway 6, to remotely monitor traffic for the project corridor and beyond
- Repositioned the traffic detection cameras at 1st Avenue/E. 9th Street to minimize false detections
- Installing traffic detection cameras at the 1st Avenue/Interstate 80 traffic signals to replace the in-pavement traffic detection wire loops (spring 2018)
In anticipation of the project, underground duct banks were proactively constructed in 2017. These duct banks provided places for the private utilities companies to relocate their overhead and underground facilities to be out of the way before the 2018 improvement projects. The duct banks should minimize delays caused by private utility relocations, which can be common during street projects.
- Sign up for e-news alerts ("Construction and Traffic Updates" category)
- Like City of Coralville, Iowa on Facebook
- Follow the City of Coralville, Iowa on Twitter
- Join Nextdoor (a private social network for Coralville neighborhoods)
- Pay attention to construction message boards along 1st Avenue during construction
- Check local news for media releases
- Attend weekly meetings with the City and the contractors, and open to the public:
- Thursdays beginning March 22, 2018
- 9:00-10:00 am
- Coralville City Hall (1512 7th St.)
- call 319.248.1720 for more information
Work on this Iowa DOT project will occur between 8:00 pm and 6:00 am, Sunday through Thursday, to minimize traffic disruptions Read on...
1st Avenue will be reduced to one lane in each direction the entire length of the project, from just south of 6th Street to just south on 9th Street Read on...
Depending on where the contractor is working, the traffic signals at the westerly Lowes driveway and at Jones Blvd. may be in flashing red mode Read on...
Beginning Sunday evening, May 13, traffic will detour using Oakdale Boulevard, Crosspark Road, & Wheaton Road Read on...
Begins Monday, April 23 Read on...
6th Street to close between 1st Avenue and Baymont Inn & Suites driveway, 1st Avenue reduced to one lane in each direction near 6th Street intersection Read on...