I knew Maryland was adding speed cameras. But until I researched today's column I didn't realize how many and by what margin we seem to be ahead of the rest of the country. According to the Insurance Institute for Highway Safety, there are "more than 106" cities, towns and counties in the United States with speed cameras. Twenty-nine of them are in Maryland.

From the column:

Maryland is also one of the few states with speed cameras on interstate highways — seven camera vehicles rotating among 10 locations. (Check safezones.maryland.gov to see where.)

Gathering state and local data, StopBigBrotherMD.org calculated this month that Maryland speed cameras generated $77 million in revenue for the fiscal year that ended June 30. That's twice as much as the state collected in alcohol taxes.

Here is the stopbigbrothermd link. Here are the locations of speed cameras on the Baltimore Beltway and other Maryland interstate locations. Here is the IIHS's maps and lists of states and localities with speed cameras and red-light cameras.

To see where the cameras are in your locality, check with the county. The places keep changing.