Caltrans wants no credit for flawed bike bridge

By R.E. GraswichApril 2025

There is no band of brothers when it comes to bridge building. In the world of concrete and rebar, it’s every man for himself.

That’s my takeaway from discussions with Caltrans about the city’s doomed bicycle bridge over Interstate 5 and Riverside Boulevard. The state transportation agency’s attitude is, whatever happens with that bridge is the city’s problem.

“The City of Sacramento is responsible for the day-to-day administration of the construction contract of the bridge,” a Caltrans spokesman tells me.

I don’t blame Caltrans for wanting to steer clear. The $12 million bridge connecting the Del Rio Trail and Sacramento River Parkway bike paths is an embarrassment.

The city—not Caltrans—ordered the bridge’s design and construction. After the discovery of substandard concrete and rebar, the city—not Caltrans—told contractors to tear the mess down and start over.

But it’s too simple to suggest Caltrans was out of town when mistakes were made. Caltrans’ fingerprints are everywhere.

State transportation engineers issued the construction permits. They created specifications for the concrete and rebar. They wrote rules about concrete core samples and strength and durability tests.

And they backed the city when questions were raised about details within those rules.

“As the oversight agency for this project, Caltrans’ role is to verify that the city is performing these responsibilities,” the Caltrans spokesman says.

There’s the problem. The city performed its duties, checked the boxes and knew early on the concrete was questionable.

But as far as I can tell, neither the city nor Caltrans were able or willing to stop construction until the bridge was more or less finished.

I want to know why work continued before the city finally pulled the plug. How this fiasco got past first base.

Inspired to dig, I reviewed nearly 2,000 pages of documents obtained under a public records request. The documents are helpful but sanitized, hollowed out by missing emails and absent attachments.

The records show the city raised early concerns about concrete mixtures. But they don’t explain what happened next—why trucks were scheduled to deliver 127 yards of concrete that didn’t pass inspection for a bridge across I-5.

Before I read the documents, I was already good at digging holes for fence posts and filling them with water and a bag of ready mix.

Fence posts and freeway bridges are cousins. Both need ready mix. Caltrans aims to make bridge construction routine by publishing technical specifications. Follow them and you’re fine.

Here’s where the I-5 bike bridge ran into trouble. The documents chronicle a dispute about whether natural pozzolan can be added to bridge concrete in place of fly ash.

The bridge contractor seemed to believe fly ash and pozzolan are interchangeable in bridge concrete. Caltrans specifications say hold on, not so fast.

Fly ash is a coal byproduct. Pozzolan is volcanic ash. Neither is suitable when baking a cake, but both can strengthen concrete. Just add water and a few other things and mix.

“We know we purchased Class N pozzolan and whatever was delivered was definitely weighed up by our scales, recorded on our weight tags, and mixed in our trucks,” the concrete supplier tells the city in an email.

The concrete guys hired a consultant—a former Caltrans engineer, imagine that—who said natural pozzolan in place of fly ash satisfies state specifications.

A Caltrans engineer responds, “I disagree that the Caltrans specifications allow the use of natural pozzolan and fly ash to be used interchangeably.”

The city stood firm. An email to the bridge contractors in July 2023 says, “We cannot authorize the use of the mix.”

Thirteen months later, the city came to a conclusion: “We have been working with our bridge designer and have determined that the Land Park Underpass Bridge cannot be accepted.”

Caltrans apparently supported the city’s decision. But it didn’t matter.

By the time the bridge was rejected, it was too late. The concrete was already poured, curing in the afternoon sun.

R.E. Graswich can be reached at regraswich@icloud.com. Follow us on Facebook and Instagram: @insidesacramento.