It should have Rolled.

Not surprisingly, you have great recollection of the various parts of the event. I'm further not surprised you would not hear the beeps from the VSC -- I imagine the road noise, etc. would overcome the warning sounds (not to mention the noise from the pounding of your own heart!).

I'm also hoping the VSC automatically shut off the cruise control. Is there any reason for a stall, though? I can see it happening in a car wtih a manual transmission, but didn't expect it in a car that readily shuts down the ICE. Perhaps it is a safety measure so there are no "live" 200+ V lines!

 

All this controversy about 8 mph over? C'mon, lighten up. We should be thankful, firstly, that everyone is fine, and that someone has yet again proven the crashworthiness of our cars for us. Wish I had VSC.

I'm not a big fan of cruise control, but that's about the only criticism I can offer here. I think I'd tend to trust the reactions of someone who's been 70 mph on skiis. And not that I'm condoning the behaviour, but as a former motorcyclist, I used to think it was a great thrill to travel at double the posted limit. And I've broken the speed limit on my bicycle. There, flame me instead.

 

Hey Hyo, I don't think there was any controversy over 8 mph. That little exchange came from the OP.

It was the situation involving a student driver that was in question.

Tom

 

Sorry to have jumped all over you, but the facts kinda hit me in the face. 70 MPH where it is posted, is conditions permitting. Conditions NOT permitting includes bad weather, car in less than perfect condition, AND elderly or very young drivers.

Last time I drove 8 miles over the speed limit? -- it was before I got my Prius. Yes I do keep to 65 on the NYS Thruway and yes I am the slowest creature there.

Anyhow, glad everyone is safe and the the Prius VSC or whatever did its thing.

 

I am glad that all the people are healthy, the car is only slightly damaged, and no other vehicles became involved!

Based on my experience with a traffic mishap at a similar age I would not rush her to drive again soon if she doesn't feel comfortable. Flashbacks are real, but they will fade over time.

The SCCA driving sounds like a great idea and I'm sure its goals are to promote caution, develop confidence, and 'new reflexes' that are more appropriate for the highway driving environment.

Prius has a relatively low center of gravity and VSC to boot. Previous posts have suggested that it is quite difficult (not impossible) to roll the car. Many modern sedans are similar; many high-center SUVs are not.

The tires were certainly subjected to unusual sidewall loading and it would be a good idea to have all 4 dismounted and carefully inspected.

Thanks for posting the story.

 

if you didn't hear beeps... it wasn't vsc...

it was traction control.. it blinks a light on the dash with no beeps... but only if the traction loss is maintained... i've seen different lengths to the flashes depending on traction...

trac will disengage cruise control and lower throttle response. vsc re adjust steering angles according to how your sliding... if you're hitting bumps and groves... trac will tend to slow you down until you're sliding very heavily then vsc kicks in

i don't like vsc in mud or gravel.. it's steer happy ( like i stated before) i'll run my car in maintenance mode.

 

A happy ending.
Now, can we all spell, "L-A-N-E A-S-S-I-S-T" ?? I wonder how far along my 2010 is?

 

Just wondering,
What would be the most proper way to recover from the situation illustrated in the opening post?

One option is to slow down then pull off the road completely, then re-enter the road when it is safe. What do you all feel?

Thanks! And glad everybody is safe.

 

Kinetic energy is proportional to the square of the velocity. The difference between 65 and 73mph is greater than the difference between 65 and 57mph. Calculating with Prius = 1400kg gives 745kJ at 73mph, 591kJ at 65mph, 454kJ at 57mph - difference is 154kJ between 73mph and 65mph, 137kJ between 65mph and 57mph. Note that the energy at 57mph is only 60% of that at 73mph.

Speed may not be that much of a factor in the causes of accidents, but it's definitely a big factor in consequences.

Having said that, the indications are that the speedometer reads 10% high so if it was indicating 73mph, it was probably only doing 66. The true speed, corroborated by roadside speed check indicators and by GPS devices, is shown in the Vehicle Signal Check screen in the MFD diagnostics.

(Incidentally this calculation indicates why regen could never recharge the battery all that well - even if you recovered all the energy at 65mph, there's only 164 watt-hours available, and air resistance is sucking up energy at a rate of around 10kW at this speed.)

 

Sounds to me from the description you give that your daughter violently over-corrected several times in generating 3 sideways slides down the 2-lane highway. That is typical behaviour for student drivers. Lucky for all of you that everything held together as the speed bled off.

Most people have no idea of the kinetic energy they acquire when driving fast. Like the guy who jumps from the top of the Empire State building says, "it isn't the speed of the fall that hurts, it's the sudden stop when you hit the ground".

 

I would like to suggest that next winter you take her out to some big empty parking lot before it gets plowed, and practice skidding. (IBM won't mind, right?) I also tend to stall cars if I skid them enough. The Prius does not skid very well, but you can get it to skid some. Your goal of course is that if she finds herself skidding on the street sometime she will not have to think about what to do, she will already be trained for it. There is also a side benefit that younger brothers/sisters in the back will think it's a thrill ride and ask her to "do it again!!"

 

Well, i guess the lack of rolling is also somewhat due to the low ground clearance, meaning low center of gravity... which of course, makes it harder to roll over.

 

Speedomoters for the USA market are accurate within 1mph as compared with GPS units.

 

They are ???? When did this start? I've had only one car (out of four) meet this standard.

 

Mine reads exactly 1 mph fast at any normal driving speed.

Tom

 

It is a twitchy car, with no deadband in the steering. When I first started driving mine I white knuckled all the way home on the highway. It took a fair amount of practice to relax. Changing to good tires helped too.

Tom

 

TOM - many have posted here that the integrity's are bad (terrible) tires.

yet, i see these tires on high level (lexus) suv's, other cars that are well over 45K+. does that mean those same integritys are just as bad? do they get other tires asap too?