Originally posted by: MercenaryForHire
Originally posted by: VirginiaDonkey
If you are following close enough to get hit by a sheet of ice coming off a car then you are................................TAILGATING ..........................and that makes it your fault!
me getting owned?....I don't know about that
looks like a bunch of " I clean off my car all the time" because in this thread it sounds like the right thing to do (hypocrites)
WROOOOOOOOOOOOOOOONG
on all three counts.
- M4H
in fairness, take 2 normal sedans
if the ice comes off the one in front, and through your windshield, you were travelling too close.
the height difference between the cars is minimal, if ice drops off it'll fall, but if your're 3-4 seconds back, like you should be in wet conditions on a motorway the ice should hit the floor long before you reach it.
thanks to laws of probability though, there is a chance that ice could get caught by the wind in a particular way and fly up into the air, before crashing down. its been in the air longer, and fallen from a higher height. its got more chance of hitting you where it hurts.
ive worked it out i think
using drag and suvat equations, its a very simplistic calc though so i might be way wrong
but i used a chunk of ice, 0.1m thick, 0.1m long, 1.5m wide
density of ice is 917kg/m cubed so its 13.75kg in mass
i said the car was 1.5m high
so dropping that ice from that height takes 0.55 seconds
then using drag and working out the deceleration at 0.1sec intervals i concluded that the ice, which leaves the car travelling 30m/s, is slowed to 26.4m/s before it hits the deck.
meaning it falls 15.5 m from the back of the car it came from. and the car behind should have a closing speed of 3.6m/s
at 70mph
using the 2 second rule, the distance between cars is consderably larger.
from a truck, whats the height of a truck. 5m say? in that case it takes 1 second for the ice to drop 5m, in that time it will of decelerated to about 24m/s, and you have a closing of 6m/s
falling 27m behind.
now all that would change depending on the size of the ice, its frontal area to the wind, whether it acted like a wing and generated lift (did not account for lift) etc etc etc and in this accident she was beside the truck so 2/4 sec rules dont really count.
the higher it is, the harder if falls though.
from a car, i doubt she'd of been hurt, or the car seriously damaged. she might of had to swerve though which on a motorway is dangerous and reason enough to remove the ice from vehicles as it is, but this fell from a lorry, with the height advantage its easier for the ice to drop onto the windshield, and its had more time to decelerate. from a car there is no height advantage and its had much less time to declerate.
so from a car behind car perspective. if you get hit with ice from the car infront, theres a good chance your following too closely. same applies with the truck, only less so since you could actually be a reasonable distance (these 2/4 sec rules are based on braking time) and still get hit.
however here, she was side by side or at least coming up next to the truck when the ice broke. which meant she had no choice but to be close.
either way it should be just common courtesy to do it, it makes everyones life easier on the road.
another hazard i think is the big rocks of ice that build up on the underside of the trailers. the big mud flaps and wheel arches seem to collect alot of dirty grotty water off the road and it freezes. over time you end up with a massive chunck of ice that eventually falls off under its own weight.
being close to the ground theres no chance of getting a face full of ice, but once they land they slow very quickly, the cars behind will have significant closing speeds so hitting one would probably mash the front of the car in. swerving to avoid it is probably just as dangerous as hitting it.