> they spent a fair amount of time controlling the distance between the
> hoses. I concluded they're doing something interesting with the time
> between the sensors

I would imagine if you use that spacing between the hoses to work
out the vehicle's speed you could use pattern matching to have a pretty
good guess at the vehicle type. Typically vehicles would be separated
by enough time to recognise a new pattern

For example, short wheelbase =3D motorcycle, long wheelbase =3D car or
van, longer wheelbase =3D light truck, long wheelbase including rear axles
short distance apart =3D heavy truck etc

Joe
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