Are there laws about where speed limit signs can be placed?

the road i got a ticket on only has one sign and it was partially covered by 2 construction signs... does that make the sign void?

Yes, every US state has laws about this. But they also have "default" laws that you are supposed to learn and know, such as the maximum speed in a residential zone, the maximum speed in a school zone, etc.

Generally, you can be cited for breaking those speed laws even where there is no sign at all.

Maybe.

The regulations about the placement of signs are state specific, and you didn't tell us where you are.

That a speed limit was not properly posted is in fact a defense to the charge of speeding. Your best bet is to take photo's of the sign, showing how obstructed it is, and take them to court with you. Persuade the judge that you legitimately didn't know there was a reduced speed limit because of the obstructed signs, and you may get off.

Warning.... in many States there is a State-wide reduced speed limit in a construction zone regardless of any signage. It could be that the sign says "35" but there's a State law that says "Don't exceed 25 in a construction zone", so that your ticket for "45 in a 35" will turn into "45 in a 25, with a construction zone enhancement" if you fight it.

Consult local counsel.

Richard

There may or may not be an actual violation with the way the sign was posted, but you still can probably get off the hook.

I would go back to that street and take a picture of the sign paritally covered (do it right away before the construciton is finished and they take the signs down).

Then take the ticket to court. Tell the judge that you didn't mean to be speeding, you simply didn't realize that the speed limit had changed. Show him the picture of the partially blocked sign. Tell him "I simply missed the sign because it was hidden from sight by the contruction signs. there is a good chance you will be let off even if there's no technical law about how the signs have to be posted.

It depends. Not being able to see it, meant that you didn't know what the posted speed limit is. However, most states have stated speed limits for residential areas, school zones, near train tracks, etc. So, if you should have known what the speed limit was without a sign, you're out of luck.