Is there a law mandating the sparsity or abundance of "Speed Limit" signs?

Question

I have seen urban roads with signs every half block and I have seen similar types of roads with signs every few miles. I assume there are federal guidlines for the population of these signs on Interstate highways.

Any links would be appreciated.

Answer 1

In general, traffic engineers like to keep the number of signs to a minimum to increase the effectiveness of the signs and to reduce distractions.

The Manual on Uniform Traffic Control Devices states in Section 2A.04: Excessive Use of Signs: "Regulatory and warning signs should be used conservatively because these signs, if used to excess, tend to lose their effectiveness. If used, route signs and directional signs should be used frequently because they promote reasonably safe and efficient operations by keeping road users informed of their location."

Answer 2

I highly doubt a federal law would be in place to mandate the number of signs are needed to inform you of state and municipal speed limits. If there was such a law, idiots would try to use it to get out of speeding tickets.

Answer 3

each city decides the number a signs they want up.