JACKSONVILLE, Fla. -- Emergency room doctors are seeing an increasing number of injuries from motorcycle crashes, and they believe one of the factors behind the increase is the price of gasoline.

Drew Roberts said he's riding his motorcycle more these days.

"For me to fill my car, that would be $40 or $50, where this bike is about $17," Roberts said.

Dr. Richard Crass, an emergency room physician with the University of Florida at Shands, said the trauma center has experienced a 37.5 percent jump in motorcycle accident injuries in April and May.

While there's a normal trend of more motorcycle wrecks in the warm-weather months, he's never seen this much of an increase. He also said the riders in the most serious wrecks don't survive long enough to make it to the hospital.

Joel Hodges, an instructor with Patriot Motorcycle Training, said as more people trade in their cars for bikes, they need to be safe. Taking a motorcycle safety course is a big part of that.

"Everything that goes into riding a motorcycle is a physical activity, and you're a lot more vulnerable," Hodges told Channel 4's Vickie Pierre.

Also critically important is wearing a helmet.

"You can't really tell in certain situations what might happen, so you can't go wrong with a helmet," Roberts said.