DEFY S. McQUAID! #68: Measured
The Question
Tom asks:
Have you ever noticed the signs on the highway which say “Begin Measured Mile”/”End Measured Mile”? What is the purpose of these signs? Aren’t the normal mileposts markers measured as well?
The Answer
It comes down to the type of road you are driving on. Interstate highways ALWAYS have the “measured mile” signposts - they are present by rule. However, state highways (such as Rte. 24 in Massachusetts, for example) and US highways (such as Rte. 1)aren’t regulated as strictly. For them, certain areas may not have the “measured mile” signposts, or the signposts may not start at the state border or the beginning of the road.
In cases such as this, the sign “Begin Measured Mile” lets the driver know that the mile signposts start HERE, and not at the state border or at the beginning of the road. It also indicates where the “official” US measurement begins - any other signposts showing mileage were installed by local or state authorities, not by the federals.
On a side note, on railroads, the “Begin Measured Mile” sign (paired with “End Measured Mile” sign) allow the engineer to check the accuracy of his speedometer by counting the time between the two signs and extrapolating his or her speed to compare against the speedometer’s measurement. Better safe than sorry, it seems…
The thing is, what is up with all the begin measured mile/end measured mile posts that only measure one mile. What do they tell you?
My research seems to indicate that it’s about the same thing they tell a train engineer - that your speedometer or odometer is working correctly.
And they make long trips across the Great Planes much more exciting!
The road between the “begin measured mile” and “end measured mile” signs is perfectly straight and flat. I believe the intent is that planes could land there in an emergency.
I suggest you provide some evidence, friend. I’ve seen measured mile signs wending their way around many a curve on Route 9 west of Worcester…