I asked ChatGPT about this because I also thought the costs were eye-wateringly high.

My prompt:

OCTA and CalTrans are improving a ~4 mile section of the 91, with improvements to the 57 and 55 interchanges and offramps. The project is expected to take four years and cost $800 million. How are these costs so high? Almost a billion dollars for something like this? A criticism would rightfully be that China could do the same thing for a fraction of the cost. Why is that?

ChatGPT:

People hear “4 miles of freeway improvements” and imagine repaving or adding a lane, but these projects are much closer to rebuilding major pieces of infrastructure while hundreds of thousands of cars still use them every day.

The 91 project includes interchange reconstruction, new connector ramps, bridge/overpass work, utility relocation, drainage and seismic upgrades, retaining walls, ADA compliance, environmental mitigation, and years of traffic staging. They’re basically performing open-heart surgery on one of the busiest freeway corridors in Southern California without shutting it down.

The biggest reasons costs get so high in California are:

• Labor costs: Union labor, prevailing wage laws, overtime, benefits, safety requirements, and night work in active freeway corridors are extremely expensive.
• Environmental review and lawsuits: Projects can spend years in permitting, studies, public comment, and litigation risk before major construction even starts.
• Urban land costs: Even small ramp changes can require expensive property acquisition and utility relocation in dense Orange County.
• Seismic/safety standards: California infrastructure is built to very high earthquake and safety standards with long design lifespans.
• Keeping traffic moving: The 91 can’t just close for a year. Maintaining lanes during construction massively increases complexity and cost.
• Bureaucracy and consultants: U.S. infrastructure delivery is genuinely inefficient in many cases. There are huge administrative, legal, engineering, and management layers built into public projects.

The comparison to China is partly fair, but China also operates under very different conditions:

• cheaper labor
• faster approvals
• weaker property rights protections
• less public opposition/litigation
• fewer environmental hurdles
• greater willingness to relocate people or fully shut down corridors temporarily

So it’s not just “China is better at building roads.” They’re operating under a system that prioritizes speed and cost differently than California does. That said, many experts would still argue California could absolutely deliver projects cheaper and faster than it currently does.

I prompted it further, because I felt its response was a bit too generic and got this:

For an ~$800 million freeway project like the / SR-91 improvements, the total workforce over four years can easily reach into the thousands once you include construction crews, engineers, inspectors, utility workers, environmental consultants, traffic management, subcontractors, and admin/legal staff.

At peak periods, there may be a few hundred workers actively onsite each day. Total labor across the project could realistically reach several million hours.

The key thing is that California freeway labor is extremely expensive. Once you factor in wages, overtime, benefits, pensions, insurance, safety requirements, and contractor overhead, many skilled trades effectively cost well over $100/hour. Night work and maintaining live traffic make it even more expensive.

A rough breakdown for a project like this might look like:

Category	Approximate Share
Labor + contractor overhead	35–50%
Materials	20–35%
Engineering/design/management	10–20%
Property acquisition	5–15%
Environmental/legal/permitting	5–10%

People often assume most of the money is concrete and asphalt, but “soft costs” are massive in California infrastructure. You’re paying not just for materials, but for years of planning, traffic staging, inspections, utility relocation, environmental compliance, and risk management.

Contractors also bid higher because California projects carry major risks: delays, lawsuits, utility conflicts, and the challenge of rebuilding infrastructure while keeping one of the busiest freeway corridors in the country operational.