The crash happened shortly before 8 a.m. Sunday in the westbound lanes of Interstate 70 at Interstate 68 in Hancock.
Maryland state police say Sen. Fetterman was driving a Chevy Traverse when, for an unknown reason, he hit the back of a Chevy Impala.
READ MORE: Pennsylvania Sen. John Fetterman and wife Gisele involved in Maryland car crash
Pennsylvania Sen. John Fetterman and wife Gisele involved in Maryland car crash
According to a police report, a witness stated that the senator passed her "traveling at a high rate of speed, well over the posted speed limit," which was 70 mph.
The report says Fetterman was "at fault" after he rear-ended the second driver, a 62-year-old woman, just before Exit 1 on I-68.
The senator and his wife, Gisele who was in the car, were taken to nearby War Memorial Hospital in West Virginia to be evaluated.
The other driver was also taken to the hospital.
Fetterman was treated for a bruised shoulder and released.
In a statement on Wednesday, Fetterman said, "This was an unfortunate accident and I'm relieved and grateful that there were no serious injuries. I need to do better and do it slower - and I will."
So far no citations have been issued.
The report said no drivers were tested for alcohol or substance use.