Bucking a national trend, fewer Ventura County commuters are driving to work alone each day than five years ago, a new survey shows.

Just why that is, the survey doesn't say.

It could be sticker shock at the gas pump, traffic congestion or a growing environmental conscience. But for whatever reason, the percentage of people driving solo to work has dropped from a little more than 80 percent in 2002 to about 75 percent this year, according to the survey done for the Ventura County Transportation Commission.

The commuter survey shows that slightly more people are telecommuting, taking the bus or simply walking to work than in 2002, said Alan Holms, who manages the commission's Ride Share carpool program.

A majority of the county's roughly 390,000 workers commute to neighboring Ventura County cities, but about 66,000 hit the road every day and head to jobs in Los Angeles County, and another 15,000 go north to Santa Barbara County, according to the survey.

The average commute time overall is about 26 minutes each way. The survey also shows that taking the train or bus requires more time, with the average commute time rising to about 45 minutes. Those numbers haven't changed much over the past five years.

While the drop in solo driving is encouraging, Holms said, there's still a hefty majority of people driving alone in their cars each day, and he'd like to see more people carpooling or taking public transportation.

"Most people say they drive alone out of convenience or simply because there's no other way to get to work," he said.

Nationally the trend is going the other way, with fewer people carpooling and more drivers going alone, according to numbers released by the Census Bureau last month.

The local numbers show that Santa Paula commuters are by far more likely to carpool than residents of other Ventura County cities. About a third of Santa Paula commuters share rides to work, compared with about 15 percent countywide.

The telephone survey of 1,017 county residents was designed to help planners map out strategies for increasing the use of alternatives to driving alone to work each day. The work was done alongside similar surveys in both San Luis Obispo and Santa Barbara counties. A slightly smaller percentage of people drive alone in Santa Barbara County, while a higher percentage go it alone in San Luis Obispo, those surveys show.

Everyone doesn't have to jump on a bus to get results, according to traffic planners. When roads are at or just above capacity, even a modest drop in the number of solo drivers can have a ripple effect on both traffic congestion and pollution.

Although it's not reflected in the numbers yet, it appears that at the least, solo commuters are interested in the possibility of either carpooling or taking public transportation.

"There are always opportunities we haven't fully explored," said Holms.

About 33,000 local residents have signed up to get Ride Share information and to be included in a database of potential carpoolers maintained by five Southern California transportation agencies.

The Ventura County Transportation Commission also offers a trip-planner service that helps personalize information for commuters and create transit itineraries, said Holms. For more information, call 800-438-1112.