Ron Lee writes:

Name one.

California, which is the model for a number of other States. Others
include Arizona, Texas, Utah, and Rhode Island.

In these States, exceeding a posted speed limit may be taken as prima
facie evidence of speeding, but it is not actually illegal. A person
cited for speeding under this type of statute may successfully defend
against the citation by demonstrating that his speed was in fact
reasonable and prudent for conditions despite being above the posted
speed limit.

There are also absolute limits, which may be universal in some States,
but may apply only to certain situations in others. For example, in
Arizona, speed limits in school zones and on highways are absolute,
but most others are subject to the "reasonable and prudent" law.

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