Possibilities versus Probabilities

Referring to the proposed waste water treatment plant (see my previous post), this letter found its way to the Waco Tribune Herald:

Sludge from Lorena
The controversy over the proposed water treatment plant in Lorena [March 21, Page 1A] should not be passed over too lightly by the people who think they are not affected.
“Leftover sludge” will be pumped into holding tanks and trucked to the city of Waco’s main wastewater treatment plant for processing. That will entail tanker trucks transporting this sludge down Highway 77 through the city of Robinson to the LaSalle Avenue water treatment plant — about a 10-mile trip.
Imagine all the possibilities. Robinson citizens may want to weigh in on this proposal, too.

Anything is possible, but is it also probable? I'll assume that the worst possible outcome of tankers full of sludge driving down 77 is one overturning and spilling it (and no I did not accidentally leave the first two letters off of that word) all over the highway. That is certainly possible, but how probable is it? I'm going to go with highly improbable because very few other trucks turn over.

If you base decisions you make (or policy decisions) on what could possibly happen, you should never drive (you could possibly suffer fatal injuries in a wreck), you should never bathe or shower (you could possibly die in a fall), you should never eat chicken (you could possibly die from salmonella poisoning), you should never walk outside while the sun is out (you could possibly get skin cancer and die), etc. People constantly do all of these things, and many other risky activities, because although possible all of these outcomes are highly improbable.