Driver who, when entering the freeway, attempts to pass every car possible via the on-ramp before merging as the on-ramp ends (despite having numerous opportunities to merge safely prior). Of course, if oneself is doing it you're an on-ramp hero. If someone else is doing it, they're simply an asshole.
Passenger in my car: "Dude! On-ramp hero. You can pass a least six more cars."
Some jerk trying to play on-ramp hero nearly caused a wreck on my way to work.
When he started ramping up, I knew it was time to beat feet & get the Hell outta there! Whilst at the concert, we started ramping up as the fevered pitch of hearing Kickass Rock Music really got our adrenaline going!