The Manchester teen was driving west on Route 2 in Glastonbury when for an unknown reason her Mazda2 left the road near Exit 10 and crashed into some nearby trees, authorities said. The woman's name was not released.
Responders were called to the scene around 9:15 p.m.
The woman was airlifted to Hartford Hospital for emergency treatment.
Police closed a portion of the road for several hours as they cleaned, cleared, and investigated the crash.
Click here to follow Daily Voice Killingly-Danielson and receive free news updates.