I-15 Work to Snarl Traffic in Daytime

To repair a freeway system deteriorating under relentless Southern California traffic, state transportation experts are experimenting with a technique that would reduce construction time but create traffic nightmares.

Instead of the typical nighttime freeway rebuilding schedule that closes one or two lanes, crews would work around the clock and shut down half the freeway.

Drivers would face gridlock, but the repairs would be finished in weeks and the lanes would be expected to last decades without major repairs. Under the old method, the repairs caused only minor nighttime delays but dragged on for months.

The state Department of Transportation plans to test the idea -- on a four-day-a-week basis -- next month on Interstate 15 near Devore. The reconstruction job is expected to add more than 90 minutes to the average rush-hour commute.

“They can’t do that,” an angry Dennis Hamilton said, nearly choking on a hot dog outside a convenience store near the freeway when he learned of the construction delays. Hamilton takes Interstate 15 every workday, delivering air compressors from his La Habra business to Oro Grande, north of Victorville.

“Traffic is going to be backed up for miles,” he said.

Despite such concerns, Caltrans officials and freeway construction experts say around-the-clock construction could become standard practice for rebuilding deteriorating urban freeways.

“We are hoping that if it goes well, we can do it again,” said Caltrans spokeswoman Rose Melgoza.

The new construction schedule -- known as the “fast track” strategy -- is the latest effort by transportation experts to solve a maddening problem: How does the state rebuild its deteriorating freeway system without creating a hellish traffic snarl?

Most of California’s freeways were built between 1955 and 1975 and were designed to last 20 years. But traffic growth, including the pounding the freeways take from a growing fleet of big rigs, has caused so much damage to some freeways that simply spreading a fresh layer of asphalt on the top is not enough.

As is the case on Interstate 15 near Devore, some freeways must be rebuilt from the gravel base up. The new construction method also allows highway officials to install high-grade concrete that lasts at least 30 years.

There are no immediate plans to use the strategy on other regional freeways until Caltrans officials and academics evaluate the results of the demonstration project.

A study by Transportation California, a coalition of highway contractors, engineers and labor unions, ranked five California cities, including Los Angeles, in the top 10 of the bumpiest rides in the nation.

“California’s urban roads are so battered by commercial and commuter traffic that they provide overwhelmingly unacceptable rides,” said Bert Sandman, chairman of Transportation California.

On most Caltrans repaving projects, road crews close one or two lanes at night, only long enough to replace the old surface with quick-setting pavement that dries in about four hours but lasts only about 10 years, according to transportation engineers.

Under the nighttime construction schedule, a freeway project like the 3.4-mile segment of Interstate 15 near Devore could drag on for about eight months. Under the around-the-clock construction schedule, the eight months would be compressed into about six weeks. During construction, freeway traffic would be diverted onto one side of the freeway while the other side was rebuilt.

On Interstate 15, eight lanes of traffic will be diverted onto four lanes for about six weeks, starting Sept. 13.

The higher-quality concrete to be used on Interstate 15 needs about 12 hours to set. But Caltrans officials and construction experts say the extra eight hours of drying time pays off in the long run because the high-strength concrete lasts longer, needing fewer repairs and road closures.

“We think you won’t have to go out there to do maintenance work for 50 years,” said Tom Salata, executive director for the western states chapter of the American Concrete Assn.

A 2003 study by engineers at UC Berkeley and UC Davis evaluated several strategies for rebuilding the section of Interstate near Devore and concluded that the around-the-clock construction schedule has several advantages over the nighttime construction strategy.

The study says the daily traffic delays will be twice as long under the around-the-clock construction plan as under the nighttime construction scheme. But the study concludes that over the long term, the around-the-clock schedule reduces overall construction costs, the duration of the work and inconvenience to motorists.

Similar around-the-clock construction techniques were tested on the Pomona Freeway in 2000 and the Long Beach Freeway last year. A 2002 study concluded that the new method cut overall construction time on the Pomona Freeway project by about 50%.

In those two cases, work crews closed the freeways for around-the-clock construction only on weekends and on much shorter stretches of roadway than the Interstate 15 project. The Interstate 15 project marks the first time that the tactic is being tested during workdays.

But Caltrans officials noted that the continuous work strategy may not be as successful on stretches of freeways where motorists have no alternate freeway routes.

Carol Thorp, spokeswoman for the Automobile Club of Southern California, said her group encourages the state to limit freeway construction to nighttime. But she said that heavy commute hours now extend further into the day and night, making it difficult for Caltrans to find any hour when traffic is light.

“These days you have to be very creative when doing any work around traffic,” she said.

Under the plan for Interstate 15, crews will close segments of the freeway long enough to tear out the crumbling pavement and replace it with a layer of high-strength concrete that’s 11 inches thicker than normal.

Interstate 15 between Sierra Avenue and the Interstate 215 junction carries an average of 110,000 vehicles per day, about 10% of which are large trucks. The slow lanes on both sides of the freeway have large potholes and bumps.

Unlike most freeways in the region, traffic on Interstate 15 remains heavy on the weekend because of motorists traveling to Las Vegas. On northbound Interstate 15, the volume on Friday afternoon grows to 68,000 vehicle trips. On Sunday afternoon, when vacationers return to Southern California, southbound Interstate 15 carries about 62,000 vehicle trips.

Because of that heavy weekend traffic, Caltrans will halt all construction and reopen all eight lanes on Fridays, Saturdays and Sundays.

Caltrans officials concede that the key to the project’s success is convincing motorists to use alternate routes or reschedule their commutes to avoid construction delays. Caltrans has already begun distributing brochures and fliers to warn motorists about the project. The state also plans to install warning signs on the freeway.

But several motorists who regularly drive Interstate 15 said they hadn’t heard of the impending project and predicted an ugly scene when the road crews begin to close lanes next month.

Others, like Daniel Lopez, who lives in Lancaster and drives Interstate 15 to visit family in San Bernardino County, were more philosophical.

“What are you going to do?” he asked. “If you need to do it, you need to do it.”