> ## Content Index
> Fetch the complete content index at: https://www.sdnewswatch.org/llms.txt
> Use this file to discover other available public pages before exploring further.

# Fact brief: Are diverging diamonds safer than traditional intersections?
- URL: https://www.sdnewswatch.org/gigafact-brief-south-dakota-diverging-diamond-interchanges-safety/
- Published: 2025-09-16T11:00:44.000Z
- Updated: 2025-09-16T11:00:43.000Z
- Description: A fact brief that refutes or confirms a claim with supporting information and additional evidence and context.
- Author: Michael Klinski
- Tags: Fact briefs

## Yes.

![](https://storage.ghost.io/c/cb/ab/cbabab5e-2dc6-462c-94a0-b72956c0d224/content/images/2025/01/WhiteFACT-BRIEF--500-x-200-px--2-1-1.png)

Diverging diamond interchanges (DDI) reduce crashes and improve traffic flow compared to traditional intersections.

There are three diverging diamond interchanges in South Dakota. The busiest two – Lacrosse Street in Rapid City and 41st Street in Sioux Falls – saw crashes fall in the year after they became operational.

Crashes were reduced by 58% in Rapid City and 73% in Sioux Falls in the months after the diverging diamonds opened.

The Sioux Falls interchange averaged more than 100 crashes a year before construction. As of June, it was on pace to have 30 crashes in its first year.

Diverging diamonds send vehicles to the left side of the road, allowing exits onto the interstate without left-hand turns across traffic. Traditional intersections have about 25 conflict points that can lead to crashes. Diverging diamonds have 14\. 

The first DDI opened in Missouri in 2009, and crashes fell 50%. 

*This fact brief responds to conversations such as* [*this one.*](https://www.reddit.com/r/SiouxFalls/comments/1gz77cn/diverging%5Fdiamond%5Fon%5F41st/?ref=sdnewswatch.org)

### **Sources**

Missouri Department of Transportation, [Diverging diamond interchanges](https://drivesmart.mdot.ms.gov/diverging-diamond-interchange/?ref=sdnewswatch.org)

KELO-TV, [Fewer crashes at SD diverging diamond interchanges](https://www.keloland.com/news/local-news/fewer-crashes-at-sd-diverging-diamond-interchanges/?ref=sdnewswatch.org)

Snyder & Associates law firm, [Safety improvements of a diverging diamond interchange](https://www.snyder-associates.com/diverging-diamond-interchange-benefits/?ref=sdnewswatch.org)

---

[South Dakota News Watch](https://www.sdnewswatch.org/) partners with [Gigafact](https://gigafact.org/?ref=sdnewswatch.org) to publish fact briefs that refute or confirm a claim with supporting information and additional evidence and context.

- [Read previous fact briefs](https://www.sdnewswatch.org/tag/fact-brief/).
- Read our verification standards and other [best practices policies](https://www.sdnewswatch.org/best-practices/).
- Submit a question for us to answer on the [South Dakota News Watch Tipline](https://gigafact.org/tipline/south-dakota-news-watch/?ref=sdnewswatch.org).
- Send questions or feedback to [factbrief@sdnewswatch.org](mailto:factbrief@sdnewswatch.org).

[Share your thoughts on this story](https://docs.google.com/forms/d/e/1FAIpQLScdTmGFf24Uhwiwd%5FndSxHkv6oBGSAy1LxF9BbwRbhBK5KflA/viewform?usp=sf%5Flink&ref=sdnewswatch.org)

*This story was produced by *South Dakota News Watch*, an independent, nonprofit organization. Read more stories and donate at* [*sdnewswatch.org*](http://sdnewswatch.org/?ref=sdnewswatch.org) *and* [*sign up for an email*](https://www.sdnewswatch.org/email/) *to get stories when they're published. *Contact Michael Klinski* at michael.klinski@sdnewswatch.org.*