Three days each week, at the tail end of the morning rush hour, Jonathan Ball drives from Pasadena to his job in Camarillo -- a journey of 57 to 64 miles, depending on his route.

Over the last few months, he has seen his speed often increase and his time on the road lessen, convincing him that traffic may be easing its grip on parts of Southern California.

“It was one of those days I took the 210 to the 118,” Ball said. “Instead of taking an hour and 15 minutes to get to work, it took an hour and 10 minutes. It was only five minutes, but I noticed it because I wasn’t even pushing it that day.”

If there has been anything that remains quintessentially unpredictable over the years in the Southland, it’s traffic. One day it’s good, the following it’s let’s-move-to-Portland awful, then it’s back to tolerable.

But a sampling of residents, traffic reporters and technical data indicates that as gasoline prices have climbed and the economy has faltered, weekday congestion has softened in some areas over the last month. There are notable decreases in commuting times on some well-traveled freeways.

Other drivers say their commutes are still bad, but that the roads are more lightly traveled at midday and evenings -- the times of day that people make discretionary trips.

The Freeway Performance Measurement System, a computer database overseen by UC Berkeley and Caltrans, provides several examples.

The morning commute from Simi Valley to Los Angeles averaged 61 minutes in April 2007 when gas cost a little more than $3 a gallon but fell to 55.1 minutes last month. Also significant are numbers from the Inland Empire, where the morning drive from Riverside to Ontario fell nearly 13% -- from 41.5 minutes in April 2007 to 36.2 minutes this April.

Also down in early May was the number of incidents reported to the California Highway Patrol in Los Angeles County -- the belly of the traffic beast. Accidents and breakdowns are thought to cause about 50% of all congestion.

In most cases, the difference in commuting times is small and typically ranges from one to five minutes.

But there is evidence of fewer cars on the road. In Orange County, Caltrans officials said that road sensors had shown a slight drop in the average number of vehicles each day on freeways such as the 91 and 405 and that toll road business was down about 6%.

The region’s ubiquitous traffic reporters are noticing a change. “Things have definitely become a lot thinner out there,” said Meghan Reyes, an airborne reporter for KNX-AM 1070 Newsradio, who first noticed a shift in late March.

On Thursday, for example, the usually busy 5 Freeway was moving smoothly through the Newhall Pass, and on the northbound 101, the afternoon traffic was backed up from the Cahuenga Pass only to Santa Monica Boulevard -- not all the way to downtown, she said.

Caltrans in Los Angeles County could not provide data on Friday because, officials said, their computer had crashed.

Traffic typically eases when a declining economy puts people out of work. In the Silicon Valley, for example, “in 2000, the 680 Freeway was one of the top two or three congested freeways here,” said Pravin Varaiya, a professor of electrical engineering and computer science at UC Berkeley who helps oversee the freeway performance database.

“When you look at it now, there’s no congestion. Something like the dot-com boom and bust were huge.”

Currently, unemployment rates are at least one percentage point higher across the region than they were a year ago. The most pronounced increase has been in the Inland Empire, where the unemployment rate in March was 7.1% compared with 5.2% a year earlier.

The latest numbers on gas sales, from January, show that consumption was down 4.5% compared with January 2007, according to the state Board of Equalization, and has been declining over the last two years. That could be an indicator that people are driving less or driving more efficient cars, or both.

Meanwhile, ridership on mass transit has continued on an upswing. Metrolink commuter trains are averaging about 46,000 passengers each weekday, up from 44,000 a year ago. “Our riders aren’t the transit-dependent,” said spokeswoman Denise Tyrrell.

“They have cars. Many of them were driving alone on the freeway.”

The number of people on buses and trains operated by the Los Angeles County Metropolitan Transportation Authority has also climbed.

The subway had 144,841 riders each weekday, an increase of about 7,000 from March ’07.

Not everyone is convinced that traffic patterns have changed. And there are exceptions. The data show, for example, that the Santa Monica Freeway has mostly worsened.

Varaiya said that although the numbers indicated there may be a decrease in commute times, a more sophisticated analysis would be needed to tell if traffic was truly trending downward.

Jeff Baugh, an airborne reporter for KFWB-AM (980), agreed that traffic has seemed lighter, but he thinks it’s because spring break for students lasts longer.

Marco Ruano, chief of freeway operations for Caltrans in Los Angeles County, said he did not have enough data to say that traffic had decreased. He also said that commute times shift as job patterns change and freeway improvements take hold.

He cited an improved 405-101 interchange that has helped the 405, in particular, and also said that increased use of ramp meters had improved speeds on the 210 Freeway.

“For some folks it might seem like they’ve noticed on a particular route that the commute is better, but on a systemwide level it’s not necessarily so,” Ruano said.

Steve Grothe, a consultant in the liquor industry, said his commute from Rancho Cucamonga to Cerritos remained stuck at 80 minutes each way via the 210, 57 and 91 freeways, with many trucks on the road. In Ojai, Al Stroberg said his drive to Westwood, where he works as an orthopedic surgeon, was still running 70 to 75 minutes.

There is one difference: He used to leave between 5:30 and 5:45 a.m., but now tries to get on the road by 5:15 to keep the commute from growing longer.

But Roberta Kramer, an attorney from Woodland Hills, said she was seeing fewer people driving, particularly at night. “If we go out on a Saturday night, I don’t see the traffic,” she said. “It doesn’t look like L.A.”

And Chuck Street, a pilot reporter for KTLA-TV Channel 5 and KIIS-FM (102.7), said that on Thursday he almost said on the air that traffic seemed lighter -- and even asked his flying partner whether gas prices had hit the magic number.

David Rizzo, a podiatrist who still makes house calls, has written a pair of advice books on escaping the death grip of Southland traffic. Rizzo’s diagnosis: The freeways are flowing again -- on Friday he saw 75-mph speeds on the 105.

“It’s not like we’re married to our cars,” Rizzo said. “When the price gets high enough we’ll change, and it’s the discretionary stuff that goes first.”

steve.hymon@latimes.com

jia-rui.chong@latimes.com

Times staff writer David Reyes contributed to this report from Costa Mesa.