

Driving around residential Connecticut we saw a lot of blind and hidden driveway warning signs. After a while, we started to wonder what the difference is between a blind driveway and hidden driveway road sign. Our guess is this: to the driver on a road, a driveway can be hidden (HIDDEN sign). And, that same driver should be careful because drivers emerging from the driveway are blind to what’s coming on the road (BLIND sign). In general, it's best to interpret both as BE CAREFUL.
We never did find a suitable but did find some fun sites where you can learn more about traffic signs:
- Manual of Traffic Signs
- Manual on Uniform Traffic Control Devices (MUTCD)
- Wisconsin DOT says signs like HIDDEN and BLIND are not in MUTCD.
- Overview of diamond signs - the photos here are from this site