Ones on city streets are legal the rest are not…..but it’s usually a good idea to follow them anyway….

What about colors and sizes of stop signs?

as long as their not silver…It doesn’t matter

I see the ones at a local shopping center. They don’t look official, They are really small and are mounted to a steel pole stuck in cement in a 5 gallon bucket and placed in strategic areas in the parking lot. I’m not sure if the same traffic laws apply there as on the public streets. The parking lot has painted lines to indicate lanes but so many drivers just blow over them in a diagonal so what are they worth? When it is obvious there is no traffic near that sign and stopping would be stupid I drive by them. The establishment would like me to put unnecessary wear and tear on my brakes, clutch, and transmission I suppose.

Depends on the state, as far as I understand it.

From here:

“Some states, including Massachusetts, Maine and Montana have specific laws that all traffic and motor vehicle laws apply on public property, as well as any private property that is generally open to the public. So, a stop sign posted in a mall parking lot would be enforceable by the police, but a stop sign posted at the end of a private driveway might not be.”

Here is whats legal and here is what is not.

Legal stop signs are a specific size and red and white in color.

Smallers yellow signs and street painted stop signs are not legal or enforceable by the police.

@john65pennington Is this a federal law, or just the law in the state where you are?

I need to know how to fnd this Federal Law, the FHWA??? Or is this legal in Texas at the Ports?