This varies from person to person, and from crash to crash. There is no such thing as a "typical" cervical sprain/strain injury. There are so many different factors involved in a collision, that its common for two people to be in the same vehicle, and suffer very different levels of injury. Individual healing time also varies greatly. Some people who have experienced a rear-end collision suffer symptoms for just a few days or weeks. Many people seem to recover in between 6 to 12 weeks. However, some people are left with long-term, or permanent injuries that can have a serious impact on their quality of life. The medical literature consistently shows that a significant percentage of people with neck injuries, as high as 20 to 30% percent, experience some long-term or chronic symptoms years after a crash.