I think that would be counter-productive and disproportionate to the actual severity of the offense itself. Emotional rather than rational. People would demand a jury trial and most would be acquitted. 

A fundamental principle of law is the punishment must fit the crime -as it is perceived by the community-, make the punishment too extreme and you lose respect for the law.  If someone runs a red -and- harms someone else, you punish for that actual harm. Punishing for what -might- have happened to almost the same degree as if it did happen opens some scary doors.