Apr 13, 2026 - News

Ask Axios: Are these traffic monitors legal?

Jason Clayworth

A photo of traffic counters. — These devices collect traffic data and are among the first steps the city takes to evaluate whether to implement measures such as speed humps to slow traffic. Photo: Courtesy of Jim Olson

Axios DSM reader Jim Olson recently noticed these devices mounted on street poles near Roosevelt High School and asked:

"Is this legal? Doesn't the police have the obligation to tell the public about these cameras?"

State of play: They are data-collection devices used by DSM's traffic department to record metrics such as vehicle volume and average speed.

The equipment is separate from the police department's mobile speed operations and is not used to issue citations.

Context: The Waveland Park Neighborhood Association recently requested that the city conduct a traffic-calming study of Polk Boulevard, where Olson noticed the devices.

The data collected will help traffic officials determine whether the city's Traffic Calming Program requirements are met, city engineer Steve Naber tells Axios.

How it works: The program is a data-driven, resident-led process.

Locations where at least 15% of drivers exceed the speed limit by more than 5 mph may be eligible for measures such as lane narrowing and additional signage.

What we're watching: Whether Polk Boulevard will join DSM's hump movement.

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Ask Axios: Are these traffic monitors legal?

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