More careful. >> very clarifying to have you here to talk about this. thank you, michael gerrard, professor of environmental law at columbia law school. thanks for helping us understand this. i appreciate it. >> thank you. we have much more ahead including the "associated press" tonight getting their hands on five hours of audiotapes from emergency dispatchers during the manmade purpose-built traffic shutdown on the george washington bridge this past fall. they've reported what's in those tapes. it's amazing. stay with us. in the nation, we reward safe driving.