In this March 10, 2013 photo, traffic is seen backed up while trying to access Interstate 15 fo …

In this March 10, 2013 photo, traffic is seen backed up while trying to access Interstate 15 fo ...

In this March 10, 2013 photo, traffic is seen backed up while trying to access Interstate 15 following the NASCAR Sprint Cup Series Kobalt Tools 400 race at the Las Vegas Motor Speedway. (Las Vegas Review-Journal, file)