Just as the price of gas has jumped this year, so has the number of motorcyclists on the road.

And with the increase comes more accidents. So far this year, 48 motorcyclists have died statewide, including two in the Yakima Valley. That's five more than last year.

But the idea that such accidents are caused by other drivers -- not the motorcyclist -- is no longer true, the State Patrol said.

Roughly 80 percent of the state's fatal motorcycle accidents are the fault of the rider and don't involve another driver, according to new research from the State Patrol.

The trend runs contrary to past research that found other motorists were mostly at fault in fatal accidents involving motorcycles.

Excessive speed, inattention, unsafe lane changes and alcohol are the top causes of motorcycle deaths, said Lt. Mike Turcott of Olympia, who began probing causes of motorcycle accidents in 2005.

And of those who died this year, 47 percent lacked a motorcycle license endorsement, he said.

"We're doing ourselves and the riding community a disservice if we don't put out accurate information," he said. "We're not going to save lives if we keep pointing the finger at the other driver. In the majority of the cases, it's clear that it's in the control of the motorcycle rider."

So far this year, there have been at least seven motorcycle accidents in the Yakima Valley in which riders have been injured. In addition, two other accidents claimed the lives of two men -- ages 23 and 26. Authorities blamed both of those accidents on operator error.

Inexperience is proving deadly as most fatalities involve younger riders on racing-style bikes or older riders who take up the hobby late in life, the State Patrol said.

There are 7,820 motorcycle endorsements in Yakima County -- a number that's grown by about 800 in the past 18 months, said Steve Stewart, state Department of Licensing motorcycle safety program manager in Olympia.

Statewide, motorcycle registrations increased 73 percent over a period spanning 1997 to 2005, while fatalities increased by 164 percent during the same period, Stewart said.

"So that was alarming to find out that fatalities increased more than registration," he said.

"There are definitely more bike (riders) out there every year," Turcott added. "And those are just the ones that are actually going in and taking the (motorcycle license) test."

Turcott said a rider can either take a written and driving test at the Department of Licensing or successfully complete a certified motorcycle safety course to obtain a motorcycle license endorsement.

Either gives riders a good overview of motorcycle safety, he said.

* Phil Ferolito can be reached at 577-7749, or pferolito@yakimaherald.com.