Results of being rear-ended at 45 MPH

[SuperGeek]

I'm glad you're mostly ok and hope your back injury isn't long term.

Question - not that I'm doubting you, but is 45mph the estimated impact speed from the police report or the normal speed limit on that road? I ask because if the Civic left 15 feet of rubber, it would have slowed down by 1/3 to 1/2 of its original speed. That would help explain why there's no apparent frame damage... but that rear crash box is only designed for 5-10mph, not 30-45... it took what it could, and transferred energy around the frame, into the engine, etc. It's quite possible a 30-40mph rear-end crash damaged lines that are nearly impossible to replace. Like the AC - it can't be installed after the factory because of its position; it's too labor intensive.

As for the braking response time on the smart, I haven't tested it fully but I've been able to go from 40-20 in about two seconds and that's without a panic. I worry that people will get the impression their cars will survive a 45mph rear impact with zero braking when in fact the speed at the instant of contact may have been more like 20.

[John_H]

SuperGeek -

What does it really matter if the impact speed were 45 or between 30 and 22? This was just the information presented the way it ... impacted our newly Smartless community member.

It it that someone looking in their rearview at the fast approaching car would think "It's okay - my Smart will protect me" and do something different?

Smarts are darned good cars that can hold up to a heck of a lot of abuse. Those who need to know - insurance folks, highway safety gurus - will have access to the full information including many details we don't know about. Getting the detail of the speed at impact nailed down won't actually help anyone here.

Unless I'm missing something very fundamental.

Also, running through the numbers assuming a 60-0 stopping distance of 134 ft (quoted recently for a Smart, perhaps valid for the impacting vehicle) ans assuming constant deceleration, the nearly 1g 28.9ft/s/s deceleration from 45mph would mean those 15 feet only reduced the speed to about 40mph in the roughly 2 tenths of a second from the start of skid to impact. Where did you figure 1/3 to 1/2 the original speed?

[tovilin]

Your license plate says "Moquito"? Really? You do know that means "small booger" in spanish right?

Glad you're ok mate.

[bull8042]

John H, I think your numbers are pretty accurate. The normal speed everyone seems to travel on that road is roughly 50 MPH, and the other driver exclaimed at one point "Man, I thought the speed limit on this road was 45"... Well, it is. But doesn't mean that people can't stop to make a left-hand turn. That being said, I am quite confident that he was travelling at least 45 MPH.
To address SuperGeek's concern, I am not nor have ever said that you shouldn't fear a rear impact. In this particular case, the Honda's bumper was perfectly aligned with the smart's bumper area. If his bumper was a foot higher, then the trunk storage area would have taken much more of the impact and possible the seat as well. A tremendous amount of the energy was transferred into motion of my smart, which in turn was transferred into the truck when it hit it.
tovilin, my wife is Hispanic and I am fluent in Spanish as well, so you are exactly correct. However, most English speaking folks who see it automatically read it as "mosquito" not realizing that they have inadvertently added a non-existant character. I always tell them, "close enough".....

[RVGRINGO]

OK, we're all curious now. How did you get the name? Queremos saber.

[jwight]

Originally Posted by John_H

SuperGeek -
Also, running through the numbers assuming a 60-0 stopping distance of 134 ft (quoted recently for a Smart, perhaps valid for the impacting vehicle) ans assuming constant deceleration, the nearly 1g 28.9ft/s/s deceleration from 45mph would mean those 15 feet only reduced the speed to about 40mph in the roughly 2 tenths of a second from the start of skid to impact. Where did you figure 1/3 to 1/2 the original speed?

As for the numbers, the best I can find for the Honda Accord (not knowing the year of the one involved here) was 60-0 mph in 132 feet. Very similar to the smart (not relevant in this case) in 130 feet. http://www.roadandtrack.com/assets/d..._rtSummary.pdf

[Godfather]

Damage to the Honda indicates it went under the rear of the smart. That also indicates a front down attitude of the Honda, characteristic of heavy braking. The skidmarks will only indicate the start and end of braking, if the end was the crash. A small deviation in the path of the skidmarks at the end will show exactly where the front wheels were at the point of impact. Between the skidmarks and measuring the damage on the moving car it is easy to calculate speed within 5 mph or so. The formulas we used will always give a minimum speed, as in "at least 55 mph". The damage to the Honda does not appear to me to be anywhere in the 45 mph range. More like 20, and slowing. Just an opinion from a retired traffic guy.

[abelenky]

Look up my accident report on this board, with pictures. (I think the subject was "Accident!"). After being rear-ended at low-speed (less than 20mph), my repairs cost $3,500, much of which was parts.

I cannot support your claim that parts would be less than $2,000. That just doesn't match my experience.

Originally Posted by Wdhitch

You need to get a new insurance company... If it's as you said and there's no frame damage... which it looks like you're right... The parts to fix would be less than $2000... I speak from experience... and you could have fixed it yourself at that.

Any chance you can keep the car?

[Mike T]

Sorry you had to go through that. These little cars are tough.

For anyone who is rear ended or who front-ends someone else, if the collision is above about 15 MPH, insist on having the engine mounts changed in the repair.

In Canada we've had some owners in that situation whose mounts were not changed, and whose engines have actually fallen to the ground either while driving or while parked. The engine mounts are part of the collision absorption system and do require replacement after a shunt.

[bull8042]

Originally Posted by RVGRINGO

OK, we're all curious now. How did you get the name? Queremos saber.

The name is for the car, not me..... hehehe
Entonces, ahorra te sabes.