If you speed through the streets of Scottsdale, here's a heads-up: The city will be using two photo-radar devices that aren't as obvious as the big white vans.

The city has been testing two photo-radar units that are the size of phone booths, contained in tan metal boxes that kind of resemble big trash cans and will be used to issue citations starting July 21.

According to a press release from the cops, these boxes will be placed in school zones.

When school's not in session, these things will be set up "near other high-traffic areas for pedestrians such as parks, pools, shopping areas, and sports fields," according to police.

The city set these things up for a test-run on Miller Road, in front of the city's Eldorado Aquatic Center and neighboring Boys and Girls Club, and drivers racked up what would have been 130 citations between June 4 and 6.

That was just a test, so no tickets were issued.

The devices, called "portable school towers," will start being used to issue citations on July 21, according to the cops.

Beware, while regular speed cameras in Scottsdale, and elsewhere, go off when you're going 11 mph over the speed limit, police say it's set at 6 mph over the speed limit in school zones.

Below, you can see the map of the fixed cameras -- not the vans -- are stationed in Scottsdale. The blue ones already exist, the light blue are speed only, the red are planned, and the yellow one is a planned speed-camera in a fixed location in a school zone.

View Scottsdale Road Safety Camera Locations in a larger map

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