Safe Speed Forums

"Once the water rises over the tyres' tread depth, there is no traction.

"In that rain he would aquaplaned at 65mph. Any driver who finds himself with water covering all four wheels is in deep trouble."

from the first article...



now then.. i've definitely driven through puddles & fords deeper than my tread depth with no problems whatsoever!
and in a landrover i've driven through wading troughs covering all four wheels (although deep trouble is a good pun i admit )

obviously i agree he's a numpty and entirely in the wrong... and the prosecution doesn't need to have been technically accurate to demonstrate this but the above statements are a bit silly.

if i recall correctly to aquaplane the amount of water entering the contact patch has to sufficiently exceed that being cleared from the contact patch, in order to build enough hydraulic pressure to support the weight on that wheel.

It doesn't make much sense does it? If you aquaplane at 65mph how do you get to 122mph?

ed-m is quite correct in his recollection.

I know, that is why I was agreeing with him. Sorry if that was not clear.

"Once the water rises over the tyres' tread depth, there is no traction.

"In that rain he would aquaplaned at 65mph. Any driver who finds himself with water covering all four wheels is in deep trouble."

This must surly depend on the weight of the vehicle v the width of the tyres and the tyre design must have an influence too.

The aqua plane speed in 10mm of water must be different for every combination of tyres and car.

from the first article...

now then.. I've definitely driven through puddles & fords deeper than my tread depth with no problems whatsoever!
and in a landrover i've (:? ) *****driven through wading troughs covering all four wheels (although deep trouble is a good pun i admit )

obviously i agree he's a numpty and entirely in the wrong... and the prosecution doesn't need to have been technically accurate to demonstrate this but the above statements are a bit silly.

if i recall correctly to aquaplane the amount of water entering the contact patch has to sufficiently exceed that being cleared from the contact patch, in order to build enough hydraulic pressure to support the weight on that wheel.

It doesn't make much sense does it? If you aquaplane at 65mph how do you get to 122mph?

Are you assuming the entire length of the carriageway is submerged in water? Unless the carriageway is designed to land the Space Shuttle, the surface will have variations of height and gradient, so they'll be some areas where the water can run off; hence the standing water will usually be in patches. One can accelerate to beyond aquaplaning speed between these patches.

Are you assuming the entire length of the carriageway is submerged in water? Unless the carriageway is designed to land the Space Shuttle, the surface will have variations of height and gradient, so they'll be some areas where the water can run off; hence the standing water will usually be in patches. One can accelerate to beyond aquaplaning speed between these patches.

New guidelines after traffic officer has conviction quashed
Tuesday, July 28, 2009, 13:45THE case of an experienced traffic officer who had his dangerous driving conviction quashed led to the issuing of new guidelines by the Court of Appeal today.
Three judges in London ruled that the "special skill" of a driver was "an irrelevant circumstance when considering whether the driving is dangerous".
Lord Justice Thomas, Mr Justice Collins and Mr Justice Owen, also pointed out that "no emergency or police duty permits a police officer to drive dangerously".
Their ruling on the issue of a driver's skills arose out of the case of Sergeant Craig Bannister, aged 30, of Briton Ferry, Neath, who was originally sentenced to five months on March 18 after earlier being found guilty of dangerous driving by a jury at Cardiff Crown Court.
He served 20 days before he was released on bail in April pending a conviction challenge which resulted last month in the Court of Appeal quashing the dangerous driving conviction and substituting one of careless driving.
His jail sentence had already been overturned at an earlier hearing by the Lord Chief Justice, Lord Judge, who said a financial penalty and not a custodial sentence should have been imposed in the officer's case.
Taking into account the fact that Bannister had already spent time in jail, he imposed a "nominal" penalty of £50.
On June 29, Lord Justice Thomas, Mr Justice Collins and Mr Justice Owen quashed the dangerous driving conviction.
They said Bannister must pay the £50 fine, but they reduced a driving ban imposed on him to three months, which he had already completed. He does not have to take a re-test.
Bannister, who qualified as an advanced police driver a month before the accident, was driving on the M4 near Swansea when his BMW 5 series spun out of control.
He received minor injuries when the car flew through the air on the night of January 13, 2008, after hitting water at 113mph.
The crown court heard Bannister was stood down from an emergency call shortly before joining the motorway, but continued to drive at high speeds, reaching 120mph.
During his trial Bannister claimed his speed was appropriate for the weather conditions, and that he was trying to find a safe place to turn off his blue lights after being stood down from the emergency call.
It was part of his case that his training had enabled him, "because of that special skill" to drive safely at speeds in those conditions "even if that would not be the case for the ordinary competent and careful driver".
Lord Justice Thomas, announcing new guidelines and the court's reasons for quashing the conviction, said that, contrary to a previous legal ruling, "taking into account the driving skills of a particular driver is inconsistent with the objective test of the competent and careful driver set out in the statute".