Does a three foot passing law actually require drivers to give three feet? Utah has a three foot passing law that states:


  Title 41 Chapter 6a Section 706.5
  
  Operation of motor vehicle near bicycle prohibited.
  
  An operator of a motor vehicle may not knowingly, intentionally, or recklessly operate a motor vehicle within three feet of a moving bicycle, unless the operator of the motor vehicle operates the motor vehicle within a reasonable and safe distance of the bicycle.


Are three foot passing laws in other states worded similarly to this?

This particular phrasing seems to legitimize excuses such "I didn't know you were there" or "I didn't mean to pass so close" or even "three inches seemed like a reasonable and safe distance to me."

Is there something about the specific legal meaning of the words that makes this law more concrete than it seems?

See also: What is the 3 foot law and which states have it?
This may not seem very concrete to you, but if you think about it, it is very powerful indeed.

Imagine a collision between a car and a bike. With no such law in place you might expect there to be some argument about whose fault it was etc. etc. and as cyclists we all know from experience who's likely to come off worst...

However you put such a law in place and when you have a collision, the motorist has broken the law by default because they couldn't have been the required distance. I'm sure there would be circumstances where the motorist could argue that the cyclist was riding like a dick, but they would be forced to make that argument, you wouldn't start from a 50/50 position.

People have been talking about this kind of thing in the UK for years in order to make cycling safer, but nothing has ever been done. In fact I think this is the first form of words I've seen that achieves this goal.