Colorado's Republican-led Senate Judiciary Committee voted 3-2 on party lines Thursday. Similar bills have been killed in recent years.
Democrats Kerry Donovan of Vail and Nancy Todd of Aurora sponsored this year's attempt in the Senate.
They argue that unprepared drivers cause frequent I-70 shutdowns that cost Colorado's economy millions of dollars — and that I-70's winter troubles threaten to drive ski tourists to competing states like Utah.
Police and paramedics supported the bill, calling it a vital safety issue.
No one testified against the bill before the committee vote. But Republican Sens. Randy Baumgartner and Ray Scott complained it had no enforcement provisions.