Based on personal observations, probably the majority were on the phone. They had a trial run for red light cameras here in the Orlando area a few months back and clocked something over 11k at 4-5 of the known worst intersections, I think it was less than a month for the trial. They now have them installed and are issuing tickets, even if you don't stop before turning on a red light. The other thing they're ticketing is when a "no turn on red" is posted and drivers turn anyway. And often you see drivers cutting through an adjacent parking lot to avoid a red light....bingo, you get a ticket in the mail. There also has been a few bikers ticketed for splitting the lanes, a move that's illegal here in Florida. After seeing an accident where a van pulled out of a driveway and the cars made room for him to cross to the opposite lanes, I can understand why they made it illegal. A guy on a bike came buzzing up between the lanes and couldn't see the van until he hit it broadside. He's now a paraplegic.
I posted on here a while back about being caught behind some young gal in a pickup, on the phone constantly and trying to check her makeup in rush hour traffic. She was hanging in the left lane and holding us up, so finally at a light I got off the bike, walked up to her open window and yanked the phone out of her hand and tossed it in the back of the truck. She started to get out but when everyone around her started to honk and applaud and yell at her, she thought better of it and just got back in the truck. Only bad part....she was so PO'd that she floored it and smoked the tires right through the redlight. Fortunately there wasn't any cross traffic, but it was at a "camera" intersection. May have been an expensive ride to work for her.
