Traffic across the Interstate 5 and Interstate 205 bridges, which has gradually ticked upward for most of the past decade, nudged down a fraction in February and dropped 3.3 percent in March, according to preliminary figures from the Oregon Department of Transportation. No figures are out yet for April or May, but those who watch the bridges each day say drives are getting easier.

“My morning commute hasn’t really felt different, but coming home traffic has been lighter,” said Vancouver Heights resident Amanda Brown, 26, who works in downtown Portland and crosses the I-5 bridge each day.

Professional traffic watchers have also noticed some extra space between the cars — traffic jams through Delta Park have declined recently, KGW Channel 8 traffic crews reported on Monday.

“Even when gas got over $3, people who said they’d make cutbacks didn’t really curtail their driving,” said Marie Dodds, director of public and governmental affairs for AAA Oregon/Idaho, which also covers Southwest Washington. “But I’ve heard anecdotally from our members that they are now making changes. Some have changed their work schedules so they don’t have to drive in peak hours, and others are looking to telecommute one or more days from home.”

More people are taking the bus as well. C-Tran gave 532,026 rides in March, up 36,500 from the same month a year earlier.

“There seems to be an increase in the number of people taking the train,” said northeast Vancouver resident Marjorie Johnson, 65, who daily drives across the I-205 bridge then takes the Max light rail to work near Portland’s Lloyd Center. “I see new faces every day. We fill the train.”

Cutting back

Fuel costs have moved up and down — mostly up — since the start of 2005, when area regular unleaded gasoline averaged $1.78 a gallon, according to AAA. But until recently, there has been no clear correlation between driving and the price of gasoline.

It may be that $3.40, not $3, was the number that finally convinced drivers to cut back.

That’s about what gasoline cost at the start of March, when traffic figures show the biggest decline in trips between Clark County and Oregon in more than three years.

In March, an average of 129,940 drivers crossed the I-5 Bridge each day. That’s down about 200 trips per day from the February, and down about 4,090 trips from March 2007.

About 134,655 drivers crossed I-205’s Glenn Jackson Bridge each day in March, down 1,079 trips per day from February and down 4,354 trips over the past year.

Fuel has climbed more than 30 cents a gallon since then.

Record-high prices

In Vancouver on Tuesday, a gallon of regular unleaded gasoline averaged $3.72, the highest price yet recorded in the area, according to AAA Oregon/Idaho. Across the Portland-Vancouver area, regular unleaded averaged $3.67. Traffic was light in both directions across the I-5 bridge.

As her afternoon progressed, Johnson spent some time thinking about the driving she would do later that day, and how much it would cost.

“I have to go to work, but we cut back how much we drive otherwise,” she said. “We try to consolidate trips and drive as little as possible.”

Courtney Sherwood is a Columbian business reporter. Reach her at 360-735-4553 or courtney.sherwood@columbian.com.