White blocks along I-15 in Farmington are geofoam building blocks

FARMINGTON, Utah —The framework of the West Davis Highway (SR-177) is looking more complete each day, with crews moving massive concrete columns and green metal beams into place over I-15 over the last several months.

But, over the last couple of weeks, drivers may have noticed large white blocks in UDOT’s work zone next to southbound I-15.

Believe it or not, the blocks are made of something a lot like Styrofoam.

“[It’s] not unlike what you see in your Igloo cooler … we call it geofoam,” said UDOT West Davis Project Director Rex Harris.

The blocks, each weighing about 200 pounds are shaping the future connecting ramp for drivers who will head southbound on the West Davis Highway onto southbound I-15 in Farmington.

Why geofoam?

Harris said they chose geofoam for this ramp since it sits right next to the railroad tracks.

Harris explained the Earth is “literally a big sponge that’s full of water … and when you put a lot of weight on it … it causes settlement.”

UDOT used lightweight concrete for the northbound connecting ramp which was built much earlier in the project construction. But, for the southbound ramp, too much weight could be bad news due to its proximity to the railroad tracks.

Harris said they’ve seen the weight of some concrete ramps cause the ground to condense by four feet.

“We can’t have four feet of settlement on the railroad tracks,” Harris said.

Geofoam is not new to Utah

This is not the first time UDOT has used geofoam for Utah roadways. The agency said they used it during the reconstruction of I-15 in Salt Lake County before the Winter Olympics in 2002.

UDOT also used geofoam on the 1100 South bridge over I-15 in Brigham City and the 5600 West bridge near 700 South in Salt Lake City.

Geofoam was first used on Norwegian roads in the 1970s. Harris said people could be driving over geofoam somewhere in the state and never know it was there.

Geofoam isn’t cheap, and because of that, it’s not UDOT’s go-to choice.  But Harris said they will use it in areas that absolutely need it, like this spot.

Another perk with geofoam is how quickly it goes up. Harris confirmed it only took crews about two weeks to start from the ground and shape an entire connecting ramp.

“They just stack the blocks on top of each other and they fit nicely … it goes up really quickly,” Harris said.

UDOT will next pour concrete around and on top of the geofoam to create the ramp people will eventually drive on.

When will the West Davis Highway be open for traffic?

The West Davis Highway will run 16 miles from Centerville to West Point, completely changing the commute for thousands of people living along that route.

UDOT’s goal is to alleviate growing congestion on I-15 north of Farmington.

The four-lane divided highway, similar to neighboring Legacy Parkway, and one of UDOT’s biggest undertakings, is scheduled to be fully completed by summer 2024.

But on Tuesday Harris announced that they hope to have the road open for drivers by the end of 2023.

“It’s great to see us be so close,” Harris said.