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
  • 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 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.


Maps & Documents

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




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. 
1st Ave lanes shifted east 04.26.18

Current & Upcoming Work*

Work completed the week of June 11:
  • Water main installation continues north of Pipeline Road within the combined Phase 2 – Stages 1 & 2 (traffic reduced to one lane in both directions from just south of 6th Street to just south of 9th Street).  The new 12” diameter water main will reach the south side of McDonald’s driveway on June 15.
  • Preparation of the pavement subbase south of the railroad crossing is nearly complete. 
  • Electrical conduit installation continues at the 6th Street intersection to serve the new traffic signals that will be installed later in the project.
Work expected the week of June 18:
  • Continue 12” diameter water main installation moving north from the McDonald’s driveway.  
  • 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.
  • Finish pavement subbase south of the railroad crossing and begin pouring concrete mid-to-late week, likely starting with 6th Street. 
Looking ahead:
  • Week of June 18, 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 (reopens 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 on August 31 (this completes the entire west half of 1st Avenue).
*Updated June 14, 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
  • Installing traffic detection cameras at the 1st Avenue/Interstate 80 traffic signals to replace the in-pavement traffic detection wire loops (spring 2018)

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. Highway 6 Resurfacing from Hawkins Drive to the Clear Creek Bridge

    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...
  2. 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...
  3. Highway 6 – Deer Creek Rd to Interstate 380

    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...
  1. Coral Ridge Avenue Detour Begins

    Beginning Sunday evening, May 13, traffic will detour using Oakdale Boulevard, Crosspark Road, & Wheaton Road Read on...
  2. Traffic Control Modification at Oakdale Boulevard & Crosspark Road Intersection

    Begins Monday, April 23 Read on...
  3. 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...
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