Glenn Highway Bridge Deck Preservation

State/Federal Project No: CFHWY00523/0001685

We are working to rehabilitate three bridges along the Glenn Highway: the northbound and southbound Knik River bridges, just south of the Glenn/Parks interchange, and the northbound Peters Creek bridge near Chugiak. All three of these bridges are over 30 years old, and two are almost 60 years old (the northbound Knik River bridge and northbound Peters Creek Bridge were both constructed in the 1960s). The bridges have potholes, ruts, and other maintenance issues that need to be repaired. The purpose of this work is to extend the service lives of the bridges, reduce maintenance costs, and enhance safety.

Work on this project will include the following:

• Repairing potholes in the concrete decks

• Installing polyester concrete overlay to waterproof the bridges and reduce corrosion

• Replacing the approach slabs to improve the driving surface

• Replacing the expansion joints, damaged drainage hardware, and guardrail as needed

• Upgrading signs and pavement markings

• Working on utilities as needed

Figure 1. An aerial photo of the Knik River bridges. Photo credit Jonathan Tymick, DOT&PF.

Work Completed So Far

Rehabilitation on both Knik River Bridges was completed in 2025. Work at the northbound Peters Creek Bridge is ongoing during summer 2026.

2026 Construction Schedule Update

The northbound (Mat-Su–bound) Peters Creek Bridge and the northbound on-ramp from Birchwood Loop Road have been closed since April 18. The closure was originally planned for 45 days to complete bridge deck repairs and resurfacing.

Once crews removed the asphalt during the initial repairs, they discovered extensive areas of weakened concrete in the bridge deck. Because of this, a full bridge deck replacement is required rather than the originally planned repairs.

Completing the full replacement now is the most efficient long-term solution. With contractors and equipment already on site, this approach helps avoid additional closures in the future, even though it will extend the current closure.

The northbound Peters Creek Bridge and northbound Birchwood Loop Road on-ramp will remain closed this summer while crews work to replace the bridge deck. We will provide schedule updates as they become available.

What to Expect During Construction

While the northbound bridge is closed, all traffic is on the open bridge. We are using the same alternating lane technique and brought back the Road Zipper machine used previously at the Knik River Bridges. Two lanes are open in the direction of peak traffic, and the Road Zipper machine adjusts the lane configuration multiple times a day. The lanes are 11-feet wide and the speed limit is 45 MPH. 

• Between 7 a.m. to 8 a.m. Sundays the barriers are shifted so there are two lanes southbound, one lane northbound
• Mondays-Fridays between 11 a.m. to noon the barriers are shifted so there are two lanes northbound and one lane southbound
• Tuesdays-Fridays between 3 a.m. to 4 a.m. the barriers are shifted so there are two lanes southbound and one lane northbound
• On Saturdays there are two lanes northbound and one lane southbound all day

Drivers who wish to avoid the narrow lanes and construction zone can detour around the area:

• NORTHBOUND TRAFFIC: Exit at Birchwood, take the Old Glenn Highway to Peters Creek, and then re-enter the Glenn Highway.
• SOUTHBOUND TRAFFIC: Exit at Peters Creek, go under the overpass to get on the Old Glenn Highway, and then re-enter the Glenn Highway at Birchwood. Note: pay attention to height restrictions to pass under the overpass.

After the bridge reopens, crews will complete work by applying the final polyester concrete overlay. Check 511.alaska.gov to view the most up-to-date traffic conditions.

Figure 2. Three lanes of traffic will be maintained on the open bridge and the middle lane will alternate directions depending on the time of day.

Traffic Pattern During Construction

During construction, drivers are encouraged to utilize the full length of all open lanes through a merging technique called the "zipper merge." Drivers remain in both open lanes of traffic until one comes to an end. Drivers in the lane that is ending use their turn signal and take turns merging into the open lane. Drivers in the open lane must consistently let drivers in the other lane merge into their lane. When correctly done, zipper merging can reduce congestion by up to 40%. Check out this video from our colleagues at the Utah Department of Transportation for a video demonstrating the zipper merge:

Figure 3. A graphic example of how to zipper merge.

The Road Zipper Machine

Our team used the Road Zipper machine last summer to help keep traffic flowing on the Knik River Bridges. This piece of equipment had never been used in Alaska before but was successful on the Knik River Bridges and will be used again on the Peters Creek Bridge. The Road Zipper machine drives down the median, picks up the heavy concrete dividers and sets them down in their new position. This allows crews to shift the median along the bridge twice a day in as little as 15 minutes! Check out this video of the Road Zipper in action on the Knik River Bridges:

The Sergeant James Bondsteel Bridge of Honor

The northbound Knik River bridge is named after Sergeant James Bondsteel, a recipient of the U.S. Medal of Honor. Born in Michigan, Sergeant Bondsteel served with the U.S. Marine Corps in Korea and then with the U.S. Army in Vietnam. His actions during the 1969 Battle of Anloc in Vietnam earned him the Medal of Honor.

After retiring in the 1980s with over 20 years of military service, Sergeant Bondsteel moved to Alaska where he worked as a counselor at the Wasilla Vet Center and the U.S. Veteran's Administration in Anchorage. Tragically, Sergeant Bondsteel was killed on the northbound Knik River bridge in 1987 at only 39 years of age when a trailer of logs became detached from a logging truck and crashed into his vehicle.

In 2002 the northbound Knik River bridge was named the "Sergeant James Bondsteel Bridge of Honor" to commemorate his life. While working on this project, we will not only preserve the structural integrity of the bridge, but also remember and honor the man it is named after, Sergeant James Bondsteel.

Frequently Asked Questions

1. Why is the northbound Peters Creek Bridge closed longer than the originally expected 45 days?

   a. When crews started removing the asphalt on the bridge for the originally planned repairs, they found extensive sections of weakened concrete in the bridge deck. This requires a full bridge deck replacement rather than the originally planned repairs. Completing the full replacement now is more efficient and helps avoid additional closures in the future, even though it extends the current closure.

2. Why are there still bumps on the approaches to the Knik River Bridges?

   a. The expansion joint is designed to sit about 3/4 of an inch below the rest of the roadway. This is necessary so that it doesn't get damaged by snowplows during the winter. For comparison, storm drain covers are designed the same way.

3. Why do the bridge decks seem unfinished and unpaved?

   a. Instead of repaving the bridges we installed polyester concrete overlay. This is a durable surface that is applied directly to the concrete. It has been used on other bridges in the state and costs less to maintain than asphalt.

4. How are you going to fit three lanes of traffic on one bridge?

   a. We will have three 11-foot-wide lanes. The opposing directions of traffic will be separated by a roughly 2-foot-wide concrete barrier.

5. Why can't you work one lane at a time and keep both bridges open?

   Part of the work that we will be doing on the bridges is replacing the expansion joints which span all the way across the width of the bridge. Traffic is not able to travel over the expansion joint when it is being replaced, which is why we must close the entire bridge during construction.

6. Why don't you work nights?

   There are certain elements of this work that require time to cure and having a night shift present would not be able to speed up that work.

7. Why aren't you widening the bridges?

   The current bridges weren't designed to be widened. To have wider bridges we would need to completely replace the existing bridges with new bridges, which would take much longer to design, longer to build, and would have been significantly more expensive.

8. Did DOT&PF buy the road zipper machine just for this project?

   No, Hamilton Construction Company, the contractor for this project, is responsible for supplying this piece of equipment.

9. Why did you reopen the Knik River Bridges with concrete that feels unfinished?

   We will be applying polyester concrete overlay to the concrete. The concrete that this overlay is applied to must cure for at least 28 days beforehand or it won't adhere properly. We finished pouring the base concrete shortly before we opened the bridge and need to give it 28 days to cure before we can apply the final overlay. We didn't want to keep the bridge closed during this 28-day curing period.

10. Will you use the Road Zipper again?

    Yes! We will be using the Road Zipper again next summer when we rehabilitate the northbound Peters Creek Bridge.

Questions?

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Want to know how construction will impact road traffic? Visit 511.alaska.gov

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