(AP) — Democratic Missouri Gov. Jay Nixon has signed a measure that could allow those convicted of driving while intoxicated to get back on the road sooner.Those convicted of offenses related to drunken driving can regain their licenses, but must use an ignition interlock device on their car for at least six months. The devices test blood alcohol content.Currently, anyone who tests above .08 or tampers with the device during the six-month period must keep the devices on their car for another six months.The measure signed Monday by Nixon changes that to require another three months of restricted driving if someone tests above the limit in the last three months of their probation.They'd need to have no violations for three consecutive months to regain full driving privileges.