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)
  • Lighting and streetscaping
Finishing 1st logo


  • 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

Traffic Impact

  • 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 late April-late August
  • The temporary traffic signals at the 1st Avenue/E. 7th Street intersection will be removed while E. 7th Street is closed and reconstructed
  • Temporary traffic signals at the new 1st Avenue/6th Street/E. 2nd Avenue intersection 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.

Contact Us

  1. Dan Holderness

    City Engineer

    Scott Larson

    Assistant City Engineer

    1512 7th St.
    P.O. Box 5127
    Coralville, IA  52241

    Ph: 319.248.1720
    Fx: 319.248.1894

    Staff Directory
1st Ave Construction Map 2018


Maps & Documents




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 to simplify the merging of 5th Street traffic turning left onto northbound 1st Avenue. 
  • E. 7th Street between 1st Avenue and E. 2nd Avenue is closed for total reconstruction. Use E. 9th Street to access the Iowa River Landing. A dedicated construction access road connected to 1st Avenue near the railroad crossing minimizes traffic impacts from the large redevelopment projects in the Iowa River Landing.
1st Ave lanes shifted east 04.26.18

Current & Upcoming Work*

Work completed the week of August 13:
  • Completed the final connection between new and existing 12” water main on 1st Avenue just south of Kum & Go’s driveway. All water services have been connected to the new 12” main.  
  • Completed southerly third of the Pipeline Road intersection paving, including the crosswalk subslab.
  • Storm sewer has reached the northerly Cantebury BP driveway.
  • Completed pouring tops for three additional storm sewer intakes south of Pipeline Road (two on 1st Avenue, one on 6th Street).  The intake throats (final step) will be poured August 17.  
  • Five of the six roadway light pole bases south of the railroad crossing have been completed.
  • Brick paver installation is ongoing at the 1st Avenue & 6th Street crosswalks and will be completed August 17 or 18.
  • The solid green areas (see image) show completed pavement as of August 16. The two yellow areas have modified subbase placed and the contractor is final grading the subbase on August 17.  These are the next two sections of mainline 1st Avenue that should be paved early the week of August 20.
1st Ave 6th St 08162018
Work expected the week of August 20:
  • Complete connection of new 12” water main under 1st Avenue to the existing 6” water main on E. 7th Street.
  • Complete all storm sewer work (including intakes) for the westerly half of 1st Avenue.
  • Complete remaining temporary pavement connections within Phase 2 – Stage 1 that are needed to transition traffic onto the new 1st Avenue pavement during Phase 2 - Stage 2.
  • Continue backfilling behind new curbs south of the railroad crossing. Grade for new sidewalk along north side of 6th Street. Form and pour new sidewalks where possible. 
  • Complete remaining street light and traffic signal pole bases south of the railroad crossing within Phase 2 – Stage 1.
  • Pave the mainline 1st Avenue segments highlighted yellow in the image above. The gaps in between these areas will be paved half at a time at a later date to maintain business access.           
Looking ahead:
  • Phase 2 – Stage 1 completion (re-opening of the 6th Street connection to 1st Avenue) is tentatively scheduled for the week of August 27.  
  • Phase 2 – Stage 2 completion (completes the entire west half of 1st Avenue) is scheduled for completion in late September.  
*Updated August 16, 2018

Merging Traffic

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"
  1. Watch for signs giving drivers notice that there is a merge ahead
  2. Stay in your lane up to the point of merge
  3. Take turns with drivers to safely ease into the remaining lane
  4. Always merge when it is safe

Merging FAQs

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

Take Turns sign

Pre-Project Planning

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
  • Installed traffic detection cameras at the 1st Avenue/Interstate 80 traffic signals to replace the in-pavement traffic detection wire loops

Duct Bank NB Lane 062017

Duct Banks

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.

Stay Informed

  1. Coral Ridge Avenue Trail Closure

    Section of trail between Holiday Rd. and Oakdale Blvd. will be closed 8:30 am-4:00 pm, Aug. 23 & 24 Read on...
  2. Upcoming Traffic Shift on Coral Ridge Avenue

    On Tuesday, August 21, there will be a shift in traffic lanes on Coral Ridge Avenue. Read on...
  3. 1st Avenue Construction Begins Next Phase on June 4

    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...
  1. Coral Ridge Avenue Detour Begins

    Beginning Sunday evening, May 13, traffic will detour using Oakdale Boulevard, Crosspark Road, & Wheaton Road Read on...
  2. 1st Avenue Construction Begins Next Phase on April 24

    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...
  3. Construction to Begin on 1st Avenue from 6th Street to 9th Street

    Northbound 1st Avenue will be reduced to one lane from just south of 6th Street to just south of 9th Street Read on...
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