Good post yesterday from Rehoboth's most famous denizen, Fritz Schranck, on highway designs, and why driving 55 miles per hour on the Big I leaves you with an odd sensation. (And I'm not talking about Sammy Hagar.)

Anyway, Mr. Schranck correctly notes:

[...] Most of the dual (4-lane) highways built since WWII used design speeds on their curves that went well beyond the 55 mph limit. In Delaware, for example, the expressways such as I-95, I-495, and the tolled portions of State Route 1 were built with 70 mph design speeds. [...]

Something which few Fearful-Americans seem to understand, besides the fact that the design speeds of interstates are relatively high, is that these design speeds were based on your average heavy, tall, narrow, skinny bias-ply tired, tiny drum-braked car designs of the day.

They don't build cars like that anymore, which is probably a good thing, as today's vehicles (even evil SUVs) are blessed with stability and safety at speeds well in excess of the original roadway design limits. An exit ramp curve designed for a safe 45 mile per hour speed in one of those old behemoths feels terribly slow in a modern car, simply because modern cars are so much better.

Don't drive in excess of posted limits, because it's illegal; but should your speed momentarily go over by a mile or two per hour, don't worry that you'll be fried to cinders by the horrible effects of velocity.

Remember, speed doesn't kill.

Sudden deceleration, on the other hand, can be very unpleasant.
posted by Terry at 11:49:00 AM