breaking news, one dead in prius crash

A friend of my wife passed away while traveling down a 4 lane highway. Fortunatly she hit a truck so those in the other vehicle weren't hurt too bad. They wondered why she crossed over, and the results of the autopsy were that she was either dead when she crossed over, or would have very soon after from an aneurism.

A year later Jersey barriers were put in due to multiple cross over head on collisions. I was grateful to see them go in, because that's a really bad straight stretch where people tend to fall asleep.

 

I don't know if your statement about breaking is true for the base model Prius but it is certainly false for the Touring model. According to the June 08 Consumer Reports the Touring model "did have better handling and breaking than a previously tested model. It got through our avoidance maneuver 3 mph faster, which puts it on par with some of the better performing family sedans." p.6

 

I always wonder if people were wearing their seat belts - but it may be it wouldn't have mattered in this case. Just the same I wish the news would harp on seat belts in most reports: we just had an needless death near my home. The driver is OK - the passenger was thrown out and died. Nothing was mentioned about seat belts in the newspaper or on TV. What does it take to get them to get the message out?

 

Interesting you mention that. When I wrote my previous entry, I thought the Prius was like most other cars. One hydraulic circuit for left front/right rear and one hydraulic circuit for the other pair. Fortunately, I checked the Prius brake training course and there were two hydraulic circuits, but not in the conventional manner. (Good reason to engage brain before mouth.) I also noticed a "Stroke Simulator" in the brake chapter. I assume this is what you were describing.

 

Furthermore, the stroke simulator is only used when the power brakes are functioning. In the event of a power assist failure, the stroke simulator is cut out of the hydraulic circuit, and the master cylinder is used to manually power both of the hydraulic brake circuits. In the event of a complete double hydraulic failure, you still have the cable operated rear parking brake.

Taking all of this into account, here is what has to happen for a complete Prius braking failure, assuming speeds above 7 mph:

1) Regenerative braking fails.

2) Electric power brake failure, including backup power from super capacitors.

3) Failure of both manual backup hydraulic circuits.

4) Failure of cable operated manual parking brake.

5) Failure of shoe leather from dragging foot outside of driver's door.

This totals up to a lot of failures. If you have this many failures, you are simply having a very bad day.

Tom

 

How are the two hydraulic circuits connected to the wheel slave cylinders? The diagram I am looking at is not at all clear.