Conflicting Witness Statements at a Signalized Intersection
Officer R. responds to a two-vehicle collision at 6:45 p.m. on a clear, dry evening; sunset is 7:10 p.m. Vehicle A (sedan) was eastbound in lane 2. Vehicle B (pickup) was westbound and turning left. Driver A states the light was green. Driver B states the light was yellow when he entered the intersection. A pedestrian witness 30 feet away says the light was red for eastbound traffic. Physical evidence: 42 feet of skid marks from Vehicle A and a debris field inside the intersection. There is no traffic camera. Both drivers deny phone use. The posted speed limit is 35 mph.
1. Which account is most consistent with the physical evidence, and which detail remains unresolved?
Read the worked answer
The physical evidence-42 feet of skid marks from Vehicle A-shows that Vehicle A was traveling at speed and braked hard before impact. At 35 mph, a typical passenger vehicle leaves roughly 40–50 feet of skid on dry asphalt, so Vehicle A’s speed was near the posted limit. The skid marks do not establish signal color. The witness’s distance and angle could affect perception, but a pedestrian 30 feet away may have a clear view. The unresolved detail is the signal status: the physical evidence supports speed and braking, not which vehicle had the right of way.
2. What single piece of additional information would most reduce uncertainty about the cause?
Read the worked answer
The traffic signal timing record for the intersection at 6:45 p.m. would show which direction had a green, yellow, or red phase. That record is objective and time-stamped, so it would directly resolve the conflicting statements about the light. If the record is unavailable, a second independent witness with a clear, unobstructed view of the signal would be the next best source. Witness memory is fallible, so the timing record is stronger evidence.