PORTLAND, OR -- We're enjoying some pretty low gas prices. But Marie Dodds of Oregon/Idaho AAA says spring is when gas prices tend to start going back up.  "Increased demand," Dodds explains. "More people are out and about driving in the better weather."

Another reason is refinery maintenance and summer tools. But while prices might rise, Dodds doesn't expect it to be dramatic.  "Does that mean that gas is going to rocket to $4 overnight? I don't think so," Dodds says. "But it could mean that we could see some periods of time where the national average remains below $3 a gallon, and maybe we pay above that mark for a time."

The current national average for a gallon of unleaded is at $2.12 a gallon. Oregon's average is at $2.32 a gallon this week.