These $250 devices help cut Des Moines crashes by 20%

Driving the news: Des Moines is now installing the backplates citywide as part of its Vision Zero initiative to reduce traffic deaths.

Catch up quick: The panels improve contrast, making signals easier to see.

• They are classified as a proven safety countermeasure by the Federal Highway Administration and are expected to reduce crashes by around 15%.
• The city in late 2023 launched plate tests at five crash-prone intersections, including locations along 19th Street and near the I-235 ramps.

By the numbers: DSM compared five years of pre-installation crash data (2018–2022) with one year after (2024) at five pilot intersections, using Iowa DOT reports.

• Average annual crashes fell from 70.2 to 56 — just over a 20% drop.
• Red light-running crashes declined from 38.2 annually to 31, down almost 19%.

Reality check: Many factors can influence crash trends.

Yes, but: The only new variable at the test sites was the backplates, giving officials confidence in the results, city spokesperson Devin Perry tells Axios.

Stunning stat: Each plate costs about $250 — thousands of dollars less than the damage from a typical crash.

State of play: DSM now plans to install the plates at 190 additional locations listed on the city's High Injury Network, which identifies areas with the highest concentration of fatal or serious-injury crashes.

• 17 intersections had the backplates as of December 2025, Perry tells Axios.

What's next: Backplate locations will continue to be added in the coming years, with 11 added by the end of 2026.