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The Incredible Shrinking Freeway Traffic Lane

August 06, 1986|BETH ANN KRIER | Times Staff Writer

Maybe you've noticed the squeeze play occurring with increasing frequency on freeways lately, the engineering maneuver in which more lanes somehow materialize out of the same amount of old pavement.

Or perhaps your ears have recently awakened to that heartening sound resembling a transmission falling out of the car--only to realize you're merely speeding over yet another ex-shoulder being born again as the freeway's newest fast lane.

You may have further observed that the creation of new corridors and their dizzying restriping seemingly has been contagious to dozens of local surface streets, where there are no shoulders to be sacrificed but where new lanes regularly appear anyway.

Have transportation engineers finally declared that smaller cars now rule the roadways, and that fewer shoulders and shrinking lanes are the answer to Southern California traffic problems? (Caltrans' officials estimate that Los Angeles-area motorists endure about 200,000 vehicle-hours of delay per day, and that's only on the freeways.)

But if lanes are, in fact, getting tinier, what are buses and big cars and vans and 18-wheeler semitrucks supposed to do?

And when was it decreed that vehicles no longer need so many shoulders to land on? While we're asking, is it possible we're being slowly conditioned to one day accept compact-car-only lanes too?

Chuck O'Connell of Caltrans and Alice Lepis and T. K. Prime of the L.A. City Department of Transportation are people with the answers, which they emphasize are only part of the solution to Southern California's growing traffic congestion.

According to these officials, freeway lanes and Los Angeles city streets are indeed shrinking in many places to make room for both more lanes and turn pockets. But the lanes are not being narrowed dramatically--usually just a cautious foot or two--in spots where it can be shown that safety hazards will not be created.

In addition, the experts indicated, lane diminishment is not accomplished by a simple decree based on the trend to smaller cars. Rather, it's a matter of complex and delicate negotiation, usually with the federal government, which still maintains specific standards for lane widths anywhere its funds have helped create a roadway.

So much for the theory that smaller cars are being recognized as King of the Road. At the newer shopping malls maybe. But not on federally funded streets and freeways.

For while many cars are indeed getting smaller, Lepis pointed out, quite a significant number of vehicles are getting larger and longer. She observed that motorists have been purchasing more vans and trucks in recent years. And that some buses, trucks and limousines are longer than ever before.

That may be one reason Lepis has heard of no proposals for compact-car-only lanes within the city. That's also why Los Angeles cannot narrow lanes that buses generally use, said the city's principal transportation engineer. (Buses are generally about 8 to 8 1/2 feet wide.)

Narrowest of All

She added, however, that inner lanes are sometimes being narrowed and that left turn lanes are occasionally becoming the narrowest of all because traffic moves more slowly in turn lanes.

But just squeezing an extra foot or so from existing lanes is generally not enough to create an entirely new aisle for automobiles. A standard surface street lane requires 10 feet, said city transportation engineer Prime, if the street is funded by the U.S. government.

Prime noted that the previous federal standard was 11 feet and that lanes constructed to that measure can now be narrowed. But even so, it typically takes considerably more than lane narrowing to create a brand-new corridor.

So how does the city materialize the extra space for new lanes?

It consults its master plan of streets and highways. As Lepis explained, when each Los Angeles city street or highway is constructed it is given a designation: major, secondary, collector or local, each of which requires a different width. "In the land development process, not all streets in the city have been built to their designated standards," she said. In short, that means a building or yard may partially and temporarily occupy what was originally intended to be roadway or sidewalk.

To reclaim these areas, Lepis added, the city generally waits until the property is being redeveloped. Then the city instructs the developer to return that part of the territory to the city so it can be used to widen the street.

Quest for Street Space

"Say, the standard full width for a major highway is 100 feet," Lepis said. "That means that there's a 10-foot sidewalk and 40 feet of roadway for a half street. Say the half street is actually constructed to be only 33 feet of roadway. That means the developer would have to dedicate seven more feet."

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