Monthly Archives: September 2010

Police Officer Makes Traffic Stop – Causes Five Cars to Crash – Chelsea, MI

I am publishing this account in hopes that police departments will think about ways to do traffic stops more safely without endangering other motorists.

What I am about to describe happened between 7:20 AM and 7:25 AM on Eastbound I-94 near Chelsea, MI on September 10, 2010. I will first describe the incident as I observed two accidents with a total of five cars caused by the officer making the traffic stop who made a very bad decision as to when and how he made his traffic stop.

I give two accounts of the incidents, the first is the timeline of my experience and observations as the events unfolded in front of me and the second is a reconstruction of a coordinated timeline of the sequence of events as best I can piece together. The incident occurred at the I-94 / US-12 exit, one exit east of the Kalmbach Road exit on I-94 near Chelsea, MI. Here is a map of the area of the accidents. The map below represents bout a mile of I-94.

At 7:20AM on September 10, the sun is perfectly lined up with eastbound I-94 and has just cleared the horizon so it is fully visible and directly over the road as you drive Eastbound. The day was perfectly clear so the driving was like looking into an arc-welder. It is a pretty unsafe situation but the traffic levels were heavy and moving smoothly right about the speed limit.

As I was coming around a curve at A on the map above, I was turning from shade directly into the sun. As I was emerging from the trees (see the tree pattern on the map), I saw a bunch of tail lights and excited lane changes including some trucks moving into the left lane and cars scattering a bit. But everyone was slowing down and finding their place in the left lane safely. Once we all got into the left lane, we could see a motorcycle policeman had pulled over a semi truck right at the beginning of the exit to US-12 (B). All of the lane changes were folks following the law that requires us to give a stopped policeman a full lane. We had less than 500 yards because of the bend in the road and the fact that there was a truck in the right lane that blocked the view of the stopped policeman there was a bit of a scramble for us all to get in the left lane – but most drivers are pretty skilled at 7:30 and we did pretty well.

As we came upon the traffic stop, it appeared that the stop had just started, the officer looked like he had just gotten off the bike to walk to the front of the trunk.

As we passed the police officer and stopped truck at (B), traffic started to go back into two lanes and gently sped back up – at this point the sun was directly in our eyes. In about 15 seconds, as I was passing over the bridge at (C) we again saw furious lane changing, brake lights and cars darting onto the shoulder as traffic ground to a halt. I came to a complete stop about 100 yards past the bridge, right at (C). We had to brake firmly to stop in time but there were no screeching of tires.

I was stopped for about 15 seconds and the line of stopped cars behind me grew at a stopped car every 2 seconds while I watched in my rear view mirror. After there were about 5 cars stopped behind me, I noticed a small car moving quite fast and spinning on the road – they clearly had locked up their brakes and were spinning around like at top at 45 miles per hour. At some point they crashed into one of the stopped cars behind me. The crash bent some sheet metal but it appeared no one was hurt.

11-09-10_093854_01.jpgAfter another 30 seconds, the traffic in front of me started to move. Three lanes of traffic (including the on-ramp from US-12) was squeezing down to one lane and driving on the shoulder to get past three wrecked cars at (D). It looked like the wreck was less than five minutes old and from the debris pattern it looked like there had been contact in all three lanes including the on-ramp. I took a picture of the furthest eastbound car as I went by at about 5 miles per hour on the right shoulder. I only took a picture after I had completely cleared the confusion of cars moving and merging.

After about 2 minutes we got by the last car and I was on my way and continued to work, thankful that I was unhurt and unscratched and knowing at least five people we having a bad day – especially the car that was in the median, quite banged up. It looked again thankfully like there were no major injuries but some quite damaged vehicles and a lot of freaked out people.


This is my best guess at a timeline for all the events that happened over a 5 minute period. These are educated guesses that fit my experience and the elapsed time as I experienced and perceived it.

I am 2 miles west of the US-12 exit, the police officer is pulling over the semi-truck.

The stop causes a lot of traffic confusion at B because of the combination of drivers going from shade to sun in their eyes, the fact that traffic was trying to get into the left lane with about 500 yards of “visual warning” because the stop was right after a pretty blind curve. Because there are trucks in the traffic, merging to one lane in 500 yards at 70MPH is doubly difficult.

The leading edge of the confused traffic has reached (D) and the problem of getting back into the correct lane is complicated by the intense sun further amplified because the road is rising slightly at (D) making appear as though you are driving directly into the sun, and the fact that traffic is merging from US-12. The incoming traffic on the exit is also in the shade until they merge onto I-94 – at which time they are immediately staring into the sun (see the tree pattern on the map). People are trying to reaccelerate to normal speed but the reduced visibility results in lots of confused brake hits. At some point, this results in three-car accident, likely triggered by a high-speed vehicle unaware that traffic is in a confused state and visibility is limited entering from the on-ramp merging into slower and confused traffic on the highway causing a cascade of panic lane changes that wrecked three cars.

At this moment, I am at (A) and encountering the back-end of the confused traffic that is unaware of the accident at (D) so it tries to reaccelerate at (B), within 30 seconds, the traffic stopped by the accident at (D) causes me to stop at (C)

There are five cars behind me and the two-car spinout accident happens behind me. This accident is almost inevitable as the column of stopped cars grows toward the (B) where there is little forward visibility and the distraction of rushed lane changes triggered by the traffic stop. There may well have been several more accidents I was unaware of between C and B as the stopped car column grew toward westward toward (A) where forward visibility was more reasonable.

Traffic starts to move, squeezing three lanes of traffic onto the far right shoulder.

I pass the cars at (D) and take the picture of the easternmost car in the median with radiator steaming and then I am back on my way to work.


The simple, obvious conclusion is that a police officer stopped a truck during morning rush hour and within 5 minutes caused a three-car pileup and a two-car accident.

What went wrong and how could this be prevented? First avoid traffic stops in rush hour traffic unless there is a very severe issue. In a sense since most of the drivers on I-94 at 7:20AM are likely there five days per week, traffic moves quickly and smoothly and efficiently – but with all of the cars and trucks with skilled drivers, the traffic density is relatively high for the speeds.

Usually this works – but with little margin for error, little perturbations can cause problems easily.

Also, officers must take the sun into account for eastbound morning commutes. For the 30 minute period when the sun is directly in the eyes of drivers – avoid anything out of the ordinary. Sun directly in the eyes reduces a drivers reaction time and awareness – if they are squinting or peering from under a sun visor – they are not fully aware of their surroundings.

In a sense, sun in the eyes is like an icy road. It is probably a good idea to avoid traffic stops on slippery roads during rush hour as a general principle – but police should be aware that sun is a very big effect when it is at the wrong angle.

Sadly if there were just a bit of clouds on the horizon this would have been averted.

If I were one of the five drivers, I would attempt to sue the State Police for negligence. There is absolutely no question that the police officer was the proximate cause of all five accidents – whether that would translate to liability is anther more complex legal question.

In my mind it is less about punishing the officer – because he had no intent to cause harm – he was just making a traffic stop and doing his job. The value of lawsuit would be that future officers would think more carefully about the safety implications of traffic stops during rush hour traffic.

It is likely if he made his traffic stop 30 minutes earlier or 30 minutes later of if there were clouds on the horizon (which there usually are), there would have been no incident. Police officer training should point out that direct sun into traffic at rush hour is as much a hazard as patches of ice on the road and should be part of the safety implications they consider when deciding to make a traffic stop.