reporter: this kind of bay area traffic is something mary masoten is seeing more than ever. pretty much if i m not leaving my house by 6:00 in the morning, it s crazy out there. reporter: she drives her prius to work from richmond to brisbane every day and that trip includes crossing the bay bridge. when you have a big chunk of water out there you live with it. reporter: in december we learned she shared that part of her commute with an extra 70,000 cars and trucks an increase of more than 2%. for all seven state owned bay area bridges, traffic grew by more than 195,000 vehicles. that s particularly interesting because we ve had slow but steady declines in toll bridge traffic every year since 2003-2004. as for the sudden u turn, sam godwell says the economy could be the driving force. maybe more commuters, maybe more deliveries being made across the bridge. reporter: officials say traffic also seems to be growing in and out of silican valley. while the extra