Red Light/Green Light

Action for damages arising out of the collision of P's and D's cars at the intersection of Commonwealth Avenue and Beacon Street. The issue is who had the green light. At trial,P calls W1 who testifies that he saw the accident and that the light was green for P and red for D. In defense, D calls W2 who testifies that he saw the accident and that the light was red for P and green for D. In rebuttal, P calls W3 to testify to W1's good reputation for truth and veracity. On D's objection, what ruling and why?