Question: Can a witness give an opinion as to the speed of a vehicle simply based upon the sound the vehicle was making?
Answer: Estimates of the speed of a motor vehicle are not matters which are the exclusive province of experts. Non-expert witnesses who have the means or opportunity of observation are allowed to testify at trial as to the speed of the vehicle. However, when the witness did not actually see the vehicle moving and only heard is an issue upon which the courts have disagreed. However, the Indiana courts hold that opinions of witnesses as to the speed of a moving object may be given only when the witness shows proper knowledge, and basing such judgment on the noise made without actual observation is not be permitted.