A two-vehicle accident overnight in Ashland County shut down all three northbound lanes of I-71 for several hours this morning.  The accident, involving a semi and another vehicle , took place just north of U.S. Route 30 shortly after 3:30am.   The good news is that according to the Ashland Post of the Highway Patrol, none of the injuries of the people involved in the crash are believed to be life threatening.  All three lanes of traffic have since reopened.  The accident remains under investigation.