KAHULUI - A dirt bike operator suffered life-threatening injuries in a collision with a pickup truck on Hana Highway Wednesday morning, less than a month after two fatal motorcycle crashes on Maui, The Maui News reported today.

With speed suspected as a factor in two of the three crashes, police Lt. Bobby Hill cautioned motorcyclists to be careful to follow the rules of the road.

"You have to ride real humbly and be defensive and watch for people," said Hill, commander of the police Traffic Section. "Understand that you're the most vulnerable vehicle on the road."

Police said a 48-year-old Makawao man was in critical condition after the collision at 10:41 a.m. Wednesday on Hana Highway at Pulehu Road. The man was operating a Kawasaki dirt bike that was heading in the Paia direction on the highway when it collided with a Hawaiian Commercial & Sugar Co. Ford F-150 pickup truck that was turning left from Pulehu Road onto Hana Highway.

The front fork of the dirt bike was pushed back in the impact, which smashed the left side of the truck bed. Police said the 50-year-old Makawao man driving the truck wasn't injured.

The dirt bike rider, who was in the intensive care unit at Maui Memorial Medical Center, was wearing a helmet, police said. Speed is being investigated as a factor in the crash, police said.

Paia-bound traffic was slowed on Hana Highway as police closed two lanes between Dairy Road and Pulehu Road for the on-scene traffic investigation. Eastbound traffic was diverted onto an outer lane until the road was reopened about two hours later.

The collision Wednesday was the third near-fatal or fatal crash on Maui roads this year, all involving motorcycles.

On Jan. 21, a motorcyclist was killed in a collision with a sport-utility vehicle on Hana Highway at Wakea Avenue in Kahului. The motorcyclist, 21-year-old Jonathan Davis of Kahului, had been wearing a helmet and heading to work in the Paia direction of the highway at 6:50 a.m. when his Suzuki sport bike collided with the vehicle turning left from the highway onto Wakea Avenue, police said.

While an investigation is continuing, police suspect speed was a factor in the collision.

At 8:37 p.m. the next day, 44-year-old Robert Aviles of Kula crashed his 1978 Harley- Davidson motorcycle while heading up Omaopio Road about 2.7 miles from Kula Highway, police said. Aviles, who wasn't wearing a helmet and was thrown from the motorcycle, died two days later in the hospital.

Alcohol has been confirmed as a contributing factor in that crash, which remains under investigation, Hill said.

He said all three crashes were "preventable."

Because of the coordination required to operate a motorcycle, Hill said riders should be especially careful on the road.

"A motorcycle is much more vulnerable because you're on two wheels and there's balance and multitasking," he said. "It doesn't make any sense to be exceeding the speed limit and not to ride carefully. Alcohol and drugs don't make good sense."

Hill said more people may be using motorcycles as transportation rather than just recreation as the economy worsens.

Higher gas prices last year also may have led more people to use motorcycles, he said.

Of the 23 fatal crashes that killed 24 people in Maui County last year, eight involved motorcycles. Motorcyclists died in all but one of the eight collisions.

Hill recommended that motorcycle operators take a safety class or other training.

"If you ride defensively, you can see the danger coming up quickly," he said. "Most of the time you have to make a decision to protect yourself."

While a motorcycle license is required to pack someone on a motorcycle or to ride at night, someone who has passed a written test to obtain a learner's permit can legally operate a motorcycle, Hill said.

"People can come off the dealership. That's why it's so important to be trained and to learn the skills and all the workings of it," he said.

* Lila Fujimoto can be reached at lfujimoto@mauinews.com.