Mrs. Martin, the 1949 Hudson Commodore 8 carrying the Low and Slow tour team, parked behind the tainter-gate section of Folsom Dam's Auxiliary Spillway.

From an airport terminal expansion in Salt Lake City to an industrial complex growing at warp speed near Reno to a sewer treatment update and the retrofit of Folsom Dam, infrastructure stewards are digging in to upgrade facilities and enhance lifestyles.

As ENR's Low & Slow tour made its way to the West Coast, an uphill climb through Donner Pass exemplified the struggle faced by many project officials to repair and improve an often rusty and forlorn infrastructure, while an impatient public nips at their heels.

In Salt Lake City, a nearly $2-billion, 10-year program to replace the 50-year-old facilities with a modern airport terminal is underway, with the goal of handling 21 million annual passengers and keeping the facility functional in the event of an earthquake, says Kevin Fauvell, project director with the Holder-Big-D joint venture that is handling preconstruction and construction services.

In addition to a new terminal, the team will build a 3,600-space parking garage, a new light-rail station, a central utility plant and new rental-car facilities.

The expansion, planned since the late 1990s, was delayed by 9/11, the economy and airline mergers, notes Michael Williams, program director with the airport. Flexibility in the design is key: "Even five years from now, things could be different," Williams says. "Future expansion is built into all areas."

At the Tahoe Reno Industrial Park—the construction site of Tesla Motors' Gigafactory—things will be very different in five years. Luke Abaffy, ENR's multimedia editor, joined the Low & Slow team before the park tour for the last leg of the journey.

"I never thought we'd build out this far," says Dean Haymore, director of community development for Storey County, Nev., about building beyond 5,000 acres of the complex. With much of the 107,000-acre park being prepared for building, Haymore says part of recent growth is a result of Tesla's site selection for its $5-billion battery plant.

"It validated Nevada as a place for technology and manufacturing. We can support these kinds of companies," he says. "We are the next place for high tech." Haymore grants most permits within a week and says part of the reason Tesla decided to build in Nevada was the state's business-friendly environment.

With construction mounting just outside Reno and Sparks, the sewer system must be capable of handling a higher daily flow rate. Heading west, the team visited the Truckee Meadows Water Reclamation Facility.

"I've worked with more than 10 plants in Southern California and haven't seen such an old plant remaining in 2014," says Kishora Panda, the site's process engineer. In 2013, two aged 24-in. mains running under the plant's foundation slab cracked. But $100 million in upgrades are allotted over the next 10 years to bring the system up to date. Scheduled tasks include replacing the aging pipes, pumps and headworks screening system, Panda says.

The facility will also harness methane gas released by solids digestion and use it to help power the site, reducing its electrical load from the grid.

Crossing into California, the team visited Folsom Dam's $900-million auxiliary spillway project, which will deliver a 200-year level of flood protection to the Sacramento region by its scheduled completion date of 2017. The project's 1,100-ft-long approach channel directs water through six submerged tainter gates that can release overflow into a 3,027-ft-long spillway chute and stilling basin to be reintroduced into the American River. The auxiliary spillway allows for flood mitigation without increasing the height of the dam reservoir.

The journey ended with a ceremony at San Francisco City Hall, where Mohammed Nuru, the city's public-works director, congratulated the team for highlighting infrastructure requirements nationwide. "There is a great need to get the word across the country that we must invest in infrastructure before we lose our assets," he says.