Only 5k's over, what difference could it make?
You never know what other drivers might do.
[ CAR CRASHES ]
We're at the Monash University accident research centre in Melbourne.
This is the driver simulator, we have a full 180 degree view including some rear views as well.
The simulator studies are quite interesting from an engineering point of view
because what we're looking at are the human factors around driving.
We're trying to think about why people do what they do.
We look at the difference between 65 kilometres an hour and 60 kilometres an hour.
It's quite common for people to think that just a small amount of speeding
over the speed limit is not significant.
I think people don't understand the maths inherently, we don't necessarily feel the maths,
I suppose you can put it, and I think most people underestimate the importance of speed
and how much small increases in speed can make a big difference in stopping distance.
And just by the use of simple mathematical equations we demonstrated that the significance
of a 5 kilometre an hour difference in initial speed translated
to 27 kilometre an hour difference in the final impact speed,
because of the way the maths works.
It is fairly simple maths, the equation is simply V squared equals U squared plus 2ax.
V squared represents the square of the final speed.
Now for the purposes of stopping distance we usually just let that equal zero,
because we are assuming that we want the car to stop.
So we end up with U squared plus 2ax equals zero and by rearranging that we end
up with the equation d is equal to U squared divided by 2a.
So what that means is that the stopping distance is proportional
to the square of the initial speed.
For a doubling in initial speed the stopping distance will increase by a factor of four.
For a tripling in initial speed so say from 20 kilometres an hour to 60 kilometres an hour,
the stopping distance will increase by a factor of nine .
So that's where the maths is showing us how important initial speed is
for stopping distance The thing that people should remember is most of the stopping is done
in the last few metres because you're still taking off speed at the same rate
but you're doing it from a much smaller base so you've already taken off a lot of speed,
those last few kilometres an hour drop away quite quickly.
By having a lower speed, initially you'll be able to get into that lower part
of the curve more quickly as well, and therefore wash off the speed that's required.
At Holden we're about to introduce forward collision alert,
which is designed to alert a driver when they're travelling too close to the vehicle
in front using a math algorithm behind all of that.
Maths and physics, are the building blocks to determine when we need
to help our drivers for safe stopping distances.
Generally people don't drive as though they're waiting for something to happen.
Often people are thinking about other things and every second that time increases
at 60 kilometres an hour you travel another 15 or 16 metres down the road
and that could mean the difference between stopping in time and not stopping in time.
Three seconds could save a person's life.
So whatever speed you're doing, do the maths.