But U.S. 95 is still not wide enough.

The wide smiles on the faces of so many drivers in recent weeks probably will fade in a few months as engineers and designers start the next great U.S. 95 widening project and the cones and construction workers return.

The problem: A chokepoint at the Rainbow curve, where northbound U.S. 95 narrows from five lanes to three.

Drivers will recognize the problem when they have to slam on their brakes as they approach the curve and squeeze with other vehicles into the three lanes.

The fatal flaw in the recently completed widening was that projected growth in the valley was outpaced by actual growth. In the late 1990s, three lanes north of the Rainbow curve were projected to be enough, said Bob McKenzie, spokesman for the Transportation Department.

"We now acknowledge the need for another lane in each direction, and the U.S. 95 (northwest) project is proposing that lane," he said.

The U.S. 95 northwest project will add lanes on U.S. 95 from Washington Avenue north to Kyle Canyon Road. The extra lanes will be high occupancy vehicle, or HOV, lanes.

The plan also calls for a new interchange at Kyle Canyon Road and improvements to the Cheyenne Avenue, Rancho Drive/Ann Road and Durango Drive interchanges.

The work will be done in two phases at a cost of about $100 million each, officials said.

Environmental evaluations for the U.S. 95 northwest widening project are nearly done; on Thursday, officials held a hearing to gather public thoughts on the project.

Optimistic projections for the start of the project put it at early 2009, depending on funding and federal approvals. If things run smoothly, the two phases would be completed in 2013.

But motorists will see work on a related interim project begin within a few months. In February, the Transportation Department will pay about $3 million to lay down a third lane in each direction between Craig Road and Centennial Parkway, officials said.

Jenica Finnerty, senior project manager for the northwest widening, said the Transportation Department realized the extra lanes were needed in 2003 and the designing began.

The recently completed widening "did not adequately meet the need. That's why this project (the northwest widening) is coming to the rescue of that problem," Finnerty said.

All this comes as a surprise to many commuters who have been hearing for weeks that construction was finished.

Tim McDonald, 47, who owns a janitorial service company and regularly commutes on U.S. 95, said he was shocked to learn of the new construction work.

"I thought they were done," he said, sitting in a white pickup just off the Craig Road exit. "Why? It seems to be running good now."

McDonald for years has tried to avoid the highway because of the construction. He and his wife, Nia, were just getting used to the open road.

"I wish they would just give us a break" from the construction, she said.

Thomas Sisk, 42, who lives near Cheyenne Avenue and U.S. 95, said he believed the construction was done until he received a letter from the Transportation Department about a month ago. "I heard every day on the radio that it was finished," Sisk said.

But Herb Thames, who owns rental property along U.S. 95, said he believed work would never end on the highway and sees that as a good thing.

"We're a growing city. We are going to have ongoing projects," he said.

Some of the northwest project will be constructed by other government entities. A new interchange at Horse Drive will be built by the city of Las Vegas. The much-needed interchange between U.S. 95 and the Las Vegas Beltway will be built by Clark County, Finnerty said.

Other notable items in the northwest widening project include ramp meters at entrances along the freeway and a park-and-ride facility at Durango and U.S. 95.

Drivers can expect at least another five to six years of construction and another hefty multimillion-dollar bill.

And that's if commuters are lucky. The most recent widening project took nine months longer than originally anticipated because of a lawsuit by the Sierra Club.

The environmental group contended that the project did not adequately consider health risks from air pollution for folks living near the highway. The lawsuit was settled out of court and construction continued.

The nine-month delay is estimated by state officials to have cost taxpayers $20 million.

"Unfortunately, the stay (by the 9th Circuit Court) occurred during a time of rapid construction price escalation," McKenzie said.

Contact reporter Francis McCabe at fmccabe @reviewjournal.com or (702) 387-2904.