This Louisiana Town Runs Largely on Traffic Fines. The Mayor Is Your Judge.

Re:This Louisiana Town Runs Largely on Traffic Fines. The Ma... by uxp8u61q on Thursday November 23, 2023 @02:04PM (#38396235)

We clearly have different experience on the road.

> Since the speed delta is the same it's far worse with 30 to 45, and regulations reflect that.

If E(v) = mv²/2, then E(v+dv) = m(v+dv)²/2 = mv² + m v dv/2 + m dv²/2. As you can see, the middle term is proportional to v, the initial speed. Kinetic energy does increase more going 90->105 than 30->45.

Maybe this is too abstract, so he're a concrete example. Let's assume a vehicle weighing 1 ton (1000 kg).

* Going 30 km/h => kinetic energy is 34 kJ

* Going 45 km/h => kinetic energy is 78 kJ, so about 43 kJ more

* Going 90 km/h => kinetic energy is 312 kJ

* Going 105 km/h => kinetic energy is 425 kJ, so about 113 kJ more

It's really basic physics.

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Re:This Louisiana Town Runs Largely on Traffic Fines. The Ma... by varjag on Thursday November 23, 2023 @04:27PM (#38397767)

Then I think you understood that 15 over 30 represents more than a doubling of the energy versus the increase by 1/3 in the (already assuringly lethal for pedestrian) 90 case.

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