A few resources,
Deflock.org has a map based on openstreetmap that shows the positions of ALPR cameras. I would highly encourage you to contribute if you find any unlisted cameras.
Dontgetflocked.com is a website for routing. It can generate navigation routes that avoid, or limit exposure to the cameras listed on deflock.org.
All of these are specific to the US and Canada. Other countries may have ALPR installations, but they are not listed on deflock.
Edit: deflock has a toggle switch for Canada. Only two countries.