A woman in her 40s suffered head injuries that are believed to be life-threatening at this time.
Officers are appealing for witnesses after a multiple-vehicle collision on the M6.
Police were called to the southbound stretch of the motorway between J3 and J2 shortly after 8.20am on Friday the 20th of January because of an incident between three cars and an HGV.
A woman in her 40s suffered head injuries that are believed to be life-threatening at this time and a teenage girl suffered minor head injuries.
Enquiries are ongoing and officers are appealing for witnesses to come forward.
Officers are also keen for anyone who has dashcam footage to get in touch.
Anyone with information should contact the force or Crimestoppers anonymously quoting incident 60 of 20 January.