SF Appeal has published the Muni onboard video recording of the collision between a Muni #19 bus and a pickup truck on Jan 5th morning. The intersection is controlled by four way stop sign. Question has been brought about who's at fault. I have reviewed the video frame by frame. I come to a clear conclusion that the truck driver was at fault. While the bus driver technically did not made a complete stop, it has the right of way. The accident was caused by the truck running the stop sign at a high speed.

The four frames below captured the action during a span of 2.8 s until the moment they collided.

• Frame 1 - 00:02:34.22
• Frame 2 - 00:02:35.02
• Frame 3 - 00:02:36.02
• Frame 4 - 00:02:37.02

At frame 1, using the trash can as a reference point, it shows the bus was right at the intersection. The truck was about half a block away. It should be immediately obvious that the bus has the right of way.

At frame 2, the bus rolled forward. The truck was still some distance away.

At frame 3, the bus proceeded across the intersection slowly. The truck still have not arrive at the intersection. It should stop and yield to the bus.

At frame 4, truck ran the stop sign at high speed and caused the collision.

Base on the video frames, I plotted the estimated position and the movement of the vehicles during this 2.8 s on a map. I estimated the bus has rolled through the stop at 8 mph. In contrast, the truck has flown through the intersection from half a block away at 32 mph.

The verdict is clear, the truck driver was driving recklessly and caused the accident.

San Francisco Chronicle has published an article with the release video titled "Crash video shows bus, pickup ran stop signs". It implies they are equally at fault. I think this is wholly a mischaracterization by failing to unambiguously call out it was the truck's fault. The bus had the right of way. Actually had the bus made a complete stop the same accident could still happen.

2010.01.07 [San Francisco] - comments (3)