The storms were over and the sun was shining. But traffic in the San Fernando Valley was at a near standstill.

Even in a town long accustomed to massive traffic congestion, the closure last week of portions of five of the seven canyon roads between the San Fernando Valley and the rest of Los Angeles was remarkable.

“I’ve worked in Santa Monica for almost seven years and last Wednesday was the longest commute ever: two hours and five minutes to go 11 miles,” said Richard Close, president of the Sherman Oaks Homeowners Association whose typical 35-minute trip turned into a nightmare. “I tried every possible street: Montana, San Vicente, Wilshire. No street worked.”

Though most of the roads were back up and running by the end of the week, the fallout from the rains again exposed a weakness in the city’s network of roadways, causing some of the worst gridlock in more than a decade.

“It’s just like the fingers on your hand – it’s so obvious that sometimes you forget they’re there,” said Bruce Ackerman, President and chief executive of the Economic Alliance of the San Fernando Valley. “Once you lose some of those surface street connections, you lose everything.”

The narrow and twisty canyon roads traversing the Santa Monica Mountains have never been an ideal alternative to the freeways, especially with the susceptibility to flooding and mudslides. But as both the Ventura (101) and San Diego (405) freeways have become increasingly clogged over the years, they serve as pressure valves for rush-hour traffic.

In 2004, the number of automobile trips on Laurel Canyon averaged 38,000 each day, according to counts taken by city’s Department of Transportation, compared with 33,000 in 1995.

“The canyon roads were never built or designed to be used as those types of roadways,” said Councilwoman Wendy Greuel. “But they have become access roads for people trying to get over the hill.”

Few alternatives

The road closures began on Monday as several days of pounding rain began taking their toll. A large boulder blocked Topanga Canyon.

Mudslides knocked out Coldwater Canyon and Laurel Canyon. Flooding slowed Beverly Glen Boulevard, and Benedict Canyon had been closed to through traffic for nearly a year as new storm drains are installed.

Lacking alternatives, commuters were left to try the freeways – if they could even get on. Cars were backed up just to get to the on-ramps, and once motorists finally made it onto the freeways, speeds were running barely 20 miles per hour in many places – when traffic was moving at all.

Close said one of his colleagues left the office at 6 p.m., “went nowhere, turned around and came back to the office. He ate dinner and set out again at 8:30 p.m., figuring it would take 30 minutes to get over the hill. It took him 90 minutes.”