The incident occurred in Walker's hometown of Miami on Friday night and left him with "serious head injuries" that he was unable to recover from.
Police reported that Walker's bike had no working lights and he was wearing dark clothing at the time of the collision with another vehicle.
"Tray was a young man with a good and kind heart," Ravens coach John Harbaugh said in a statement. "He was humble and loved everything about being part of the Ravens' team. He loved his teammates, the practice and the preparation, and that showed every day. He was coachable, did his most to improve and worked to become the best.
"I'll never forget that smile. He always seemed to be next to me during the national anthem; then we would give each other a big hug. May he rest in the Peace of Christ Jesus forever."
Walker featured eight times for the Ravens last season, recording two tackles.