Self-explanatory (and probably baked, though I can't find any references).
State, community, organizationally or commercially sponsored road signs with trivia questions (and, subsequently, answers). They could be general knowledge, but probably would relate to the sponsor or geographic area in some way.
Questions would have to be short! ("What happened here in 1839?", "For whom is Polk county named?")
Post the questions and answers a mile to two apart so travelers have time to consider the question. Hilarity ensues when vandals re-arrange questions and answers.-- phoenix, Feb 22 2008 What highway was formerly known as "IL-142A"? http://www.n9jig.com/trivia.htmlIllinois Highway Trivia. It's entirely different from the idea. I hope. [Amos Kito, Feb 22 2008] Burma Shave http://en.wikipedia.org/wiki/Burma-Shave [xenzag, Feb 22 2008] The Bloody Benders of Labette County, KS http://www.legendso...istoricalMarker.jpgA favorite historical marker. [baconbrain, Feb 22 2008] Nebraska http://i209.photobu...nbrain/ArborDay.jpgHome of Arbor Day [baconbrain, Feb 22 2008] Sheesh, just stick a TV in the front seat. That should keep you occupied!-- DrCurry, Feb 22 2008 There are roadside historical markers scattered all over America, that SUPPLY this sort of information. Not a lot of folks stop at them. Google "historical marker" or see link to a fun one.
Expecting passing motorists to already know the local trivia is kind of silly. Expecting them to stop twice would be just strange, especially in America.
Building and maintaining bigger informative signs so folks don't have to stop is more expensive, and is already being done, for some reason. Nebraska, for instance, is home of Arbor Day (link). Moran, Kansas, is the hometown of the 1968 Miss America--that was on the city limit signs for many years. Two towns in Kansas have signs claiming to be the hometown of the same musician. Springfield, Missouri, has signs announcing it to be home of the state governor . . ..
If you want to play sign games, you can always guess a town's population, then read it off the city limit sign. Or, in some states, guess the elevation of the town, then read the city limit sign (especially fun if you are the only one who can see the GPS unit). Or guess the origins of the town or county name, then find the historical marker. [ ]-- baconbrain, Feb 22 2008 Bluetooth the info to a receiver in the car.-- Noexit, Feb 22 2008 Good one. Or make a low-power radio transmitter.-- baconbrain, Feb 22 2008 What's your braking distance at 110Kmph, and is it less than the 50 meters you have till the next major reason you need to know this? (hint: just reading this has taken another 250 meters)-- Dub, Feb 25 2008 As I read it, you're not meant to stop, just read the suitably large writing on a billboard as you sail by (on straight stretches without junctions one hopes).-- squeak, Feb 27 2008 random, halfbakery