On 21/05/2019 06:14, Bret Cahill wrote:
On a /m^2 basis or road damage basis?

CIA

Part of the problem in the UK is that it has become fashionable for
people to move out of town into country areas and buy cars that are
too wide for the roads.

Someone needs to do a formal study on it to get the actual numbers
but the reason they buy oversized cars in the U. S. is they are too
fat to fit into a normal car.

Once upon a time American and European cars were a different size.
European cars were a better fit for European roads.

Have you ever tried to wear a suit that's 2 - 3 sizes too small?

The useful interior of a car doesn't correlate with the outside
dimensions. When cars did not have central locking and it was possible
for the driver to reach across to operate the passenger door lock. Most
of the extra width has just put more air between driver and passenger.

With my own informal observations I get a correlation coefficient of
~ 0.9 for the junk food in the shopping cart vs obesity
relationship. Guessing not so wildly the correlation coefficient must
be at least 0.8 for the obese driving oversize motor vehicles.

The commercial aircraft industry struggles in vain to get the lard
off the runway. I feel sorry for Boeing, GE, Airbus, RR, Pratt,
etc. No matter how big they make the fans the passengers just keep
getting heavier.

....and if the airlines charged for the total weight of passenger and
luggage, the politically correct brigade would shout "discrimination!".

It's getting more and more difficult to design a plane where the
props or fans don't hit the runway. The engines are already almost
as large as the fuselage. Sooner or later they will have to go VTOL
with props designed to disintegrate on impact on emergency landings.

Increasing bypass makes the engine more efficient. Whereas the car
industry only has to concern itself with consumer vanity and paying lip
service to government regulations, the commercial aircraft industry has
to concern itself with operating costs.