It is a lethal mix of high-speed interstate traffic, sudden weather changes coming off the Black Hills, and—for two weeks every August—hundreds of thousands of motorcycles sharing the road with semi-trucks. But the interstate isn't the only red zone. From the "Malfunction Junction" of Sioux Falls to the rural gravel traps of the East River, here are the roads you need to watch out for in 2026.
1. The "Rally Alley": I-90 (Sturgis to Rapid City)
This short corridor sees more fatalities per mile than anywhere else in the state.
- The Danger Zone: Exits 37 through 46.
- The August Surge: During the Sturgis Motorcycle Rally, this road transforms. The speed limit is 80 mph, but the mix of bikes, RVs, and distracted tourists leads to catastrophic chain-reaction crashes.
- The Winter Trap: This area sits in the shadow of the Black Hills. It creates a micro-climate where "Black Ice" forms on the bridges and overpasses long before it forms on the rest of the plains.
- The Stat: In a single decade, this 9-mile stretch saw nearly 20 fatalities—a massive number for a rural state.
2. The Intersection List: 2 Spots to Watch
South Dakota's cities are growing faster than their roads can handle, creating massive congestion points.
A. 41st Street & Louise Avenue (Sioux Falls)
If you live in Sioux Falls, you avoid this intersection at all costs.
- The Nickname: Locals simply call it "The Mess."
- The Problem: It is the busiest intersection in the entire state.
- The Risk: It sits between the Empire Mall and the interstate. The sheer volume of traffic means that red-light running is constant, and rear-end collisions are a daily occurrence as frustrated shoppers try to force their way into the turning lanes.
B. Catron Boulevard & Highway 16 (Rapid City)
In West River, this is the notorious spot.
- The Hazard: It is the gateway to the Black Hills and Mt. Rushmore.
- The Risk: You have tourists in rental RVs trying to turn left across a high-speed divided highway. The sightlines are tricky, and T-bone accidents here are frequently severe.
3. The Rural Killer: The "Uncontrolled" Intersection
In the eastern half of the state ("East River"), the danger isn't traffic—it's the lack of signs.
- The Danger: South Dakota has thousands of miles of gravel section lines. Many intersections have no stop signs (uncontrolled).
- The Law: Yield to the vehicle on the right.
- The "Corn Blindness": In July and August, 7-foot-tall corn stalks block visibility at the corners.
- The Result: Drivers assume no one is coming on the lonely gravel road and blow through the intersection at 55 mph. If two trucks meet, the result is almost always fatal.
4. The Wildlife Hazard: US-14 (The Pheasant Belt)
While deer are a threat everywhere, South Dakota has a unique biological danger on highways like US-14 and US-212.
- The Threat: It isn't just one deer; it's the herd.
- The Stat: South Dakota consistently ranks in the top 5 states for animal collisions per driver.
- The Warning: In November (hunting season), pheasants and deer are constantly on the move, flushed out by hunters. Driving at dawn or dusk during pheasant season requires hyper-vigilance.
How to Survive the Drive
- Slow Down at Exit 37: If you are near Sturgis in August, drop your speed. The traffic stops suddenly, and motorcycles are hard to see in your blind spot.
- Wait Your Turn at 41st: In Sioux Falls, do not try to "squeeze" through the yellow light at Louise Ave. You will get stuck in the box and block traffic (or get hit).
- Treat Gravel Like Ice: On rural roads, gravel moves under your tires just like snow. If you corner too hard, you will roll. And always slow down at the intersection, even if you don't see a stop sign.