Jeez, I hope this doesn't last too long

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I have no concept of what 14% grade is. What is that in degrees? Or rise over run?

I’ve seen those signs before in eastern Tennessee between Chattanooga and Nashville, and also in Pennsylvania around Bethlehem. I know when the number’s above 10, it’s pretty friggin steep. I was also driving a moving van through Kentucky one time and couldn’t maintain 30 MPH on the interstate on an incline.

Of course, I live in a place where you can park in neutral and not set the parking brake and your car will probably not move an inch.

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14% means the road drops 14m if you drive 100m. That is pretty steep.

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What is that in feet? :lol: j/k

Yes, that’s pretty steep. I did some research and the steepest grade on the U.S. Interstate system is 8%, and I have driven it (I-24/US-41/64 Westbound over Monteagle Mountain, TN).

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For comparison, and I’m sure you drove it, the natural grade of Lombard St is 27% but the effective grade is 14% to 16%.

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What the hell are trucks doing on that road?!

Where is that? I want to make sure I avoid it.

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We have 33% locally, and higher elsewhere.

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I hope that it’s just a picture of a truck, placed there to cast fear into the hearts of anyone who attempts to drive that road.

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FLAT LANDER!!! :lol:

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Sign says “Trucks use lower gear”.

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It works, doesn’t it?

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LOL looks like an Australian sign.

Its looks like a far kenworth it road.

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“Trucks TURN AROUND NOW” would work better.

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14% grade: arctan(0.14) = 8 deg.
27% grade: arctan(0.27) = 15 deg.
33% grade: arctan(0.33) = 18 deg.

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So would 100% be 45 deg. or 90 deg.?

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I imagine it would be 45deg where rise=run. Or run=fall. :o

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Fall is right in that case. At that angle, I don’t think anyone would be rising.

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100% grade (1m down for 1m forward): arctan(1.00) = 45 deg.

The “grade” of a vertical cliff is infinite.

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1m down for 1m of road? 90 degrees, of course.

Edit:
Oops, my bad. Definition uses horizontal movement, not length of road.

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Actually, you did say “length of road” (hypotenuse?) in your first post, but everything else involving pitch or grade is measured rise over run, so I suppose this would be too.

It’s been 23 years since my last geometry class…