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A smooth idea for the 710 Freeway

Caltrans is thickly layering different mixes of asphalt atop the damaged old concrete to resurface the bone- (and coffee-) jangling roadway.

September 30, 2009|Thomas Curwen

The sensation is palpable, if not slightly remarkable.

There you are hurtling southbound in the No. 3 lane on the Long Beach Freeway. Your car is rattling, your tailbone jumping to the rhythm of a concrete washboard abused by years of heavy trucks and piecemeal repairs.

Then it happens, between the 105 and Rosecrans. You hit a bump, and suddenly your tires purr, your coffee settles in its cup and the radio reception seems more crisp. You may not know why -- it is the nature of freeways that we seldom consider their mechanics -- but you are now experiencing the I-710 Long Life Pavement Project, as Caltrans calls it.

Begun in 2001 and scheduled for completion in the next five years, the transformation of one of Southern California's most neglected freeways is hardly an exercise in speed.

Think of it instead as a projected $650-million art installation with its centerpiece an asphalt roadway set in a sea of concrete; and with a new phase rolling out next month, more commuters will discover what is arguably the smoothest ride in the state -- and a possible model for freeway reconstruction in the years ahead.

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Unless you're a location scout for a gangster noir, there is nothing appealing about the 710 Freeway.

Taggers find its sound walls, railroad crossings and unguarded billboards enticing canvases. Adjacent neighborhoods have long complained of the pollution it throws off, and when the center divider was a mere sliver of timber and metal, it was the scene of a number of tragic head-ons.

The roadway is a Braille text of rain grooves and uneven seams. Concrete slabs, broken into pieces like shattered panes of glass, have been replaced or resurfaced with an overlay of asphalt. It resembles a postmodern Mondrian in black and white, and it produces wobbles and vibrations that have prompted some drivers to switch to the 110 or the 605.

When John Harvey drove the freeway more than 10 years ago, his reaction was no different than most commuters'. It was so rough, he recalls, "that it hurt to drive it at 55 mph," and the number of trucks made the experience scary.

Harvey is one of the architects of the new roadway. In addition to teaching engineering at UC Davis, he is the principal investigator at the UC Pavement Research Center, a little-known testing facility in Northern California. Working beside him is a team of engineers including Carl Monismith, regarded in some circles as the dean of California pavements.

Monismith, 83, belongs to the generation of engineers who transformed California in the '50s and '60s. Their work was made easier by a Legislature that felt comfortable raising gasoline taxes and automobile registration fees, and they dreamed big.

By September 1950, according to historian Kevin Starr, the state was spending nearly $100 million a year on its highway program. When the first segment of the 710 Freeway opened in '52, it was but a small chapter in what Starr calls "an epic of freeway construction" that would define California.

In the succeeding decades, resources have dwindled, forcing younger engineers like Harvey to do more with less, or as a professor once told him: "An engineer is a person who can do for 50 cents what any damn fool can do for a dollar."

Economizing sometimes took the form of piecework, until in 1998 Caltrans decided to develop a more substantive strategy for fixing its deteriorated freeways. The agency singled out the 710 Freeway and assembled pavement designers, specialists from paving industries, academics, engineers and contractors, and began listening to proposals.

The prospect of repairing the 710 was daunting because of the challenges of the job site.

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In engineering jargon, the 710 is one of the most heavily loaded highways in the state.

On any given weekday, nearly 155,000 vehicles stream north and south on the 710 past Pacific Coast Highway, 16% of which are 18-wheelers carrying up to 40 tons to and from the Port of Long Beach and the Port of Los Angeles.

Given this volume, Caltrans divided the rehab into phases and weighed the options for rerouting traffic. Recommendations included closing the freeway in increments and diverting truck traffic into the channel of the Los Angeles River.

The agency finally settled upon a weekend schedule that diverted southbound traffic into two of the four northbound lanes, switching direction on different weekends, allowing one side to be shut down completely for construction.

More significantly, though, Caltrans chose asphalt over concrete for the job.

Engineers will argue that every road is sui generis, that no one material -- asphalt or concrete -- can be perfect for all environments. Such factors as ambient temperatures, costs, traffic and construction space have to be considered, and though 94% of the 2.27 million miles of the paved roads and highways in the country are surfaced with asphalt, California is slightly different.

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