South Dakota Doubles and Triples Test
Learn how to handle two or three trailers across South Dakota's I-90 crosswinds, grain elevator turns, and winter black ice — before you sit for the test.
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20 questions, 80% to pass, 25 minutes. South Dakota's Doubles and Triples test covers coupling, off-tracking, and wind stability on roads like I-90 and US-212.
Key Topics
- •Coupling and uncoupling dolly
- •Off-tracking & crosswind stability
- •Braking distances & weight distribution
About the South Dakota Doubles and Triples Test
Topics Covered
- ✓Coupling and uncoupling procedures — South Dakota examiners want the exact sequence for hooking up a dolly, especially when you're doing it on a gravel lot next to a grain bin.
- ✓Off-tracking and turning radius — Longer combinations cut corners hard. Know how much space you need to clear the curb at a Mitchell elevator without climbing the sidewalk.
- ✓Wind stability and rollover prevention — I-90 west of the Missouri River can gust over 50 mph. Empty trailers catch the wind and flip. The test asks how to prevent that.
- + 3 more topics
📘 Study Tips & State Info
South Dakota's Doubles and Triples test is more than memorizing steps. You need to understand why each step matters. For example, when you're coupling, the order of hooking air lines versus electrical lines isn't random — it's about safety. The examiners in Pierre will ask 'what happens if you do it backwards?' Know that.
Focus on the dolly. The converter dolly is where most mistakes happen. Practice the sequence: back under, lock the pintle hook, connect safety chains, hook air and electrical, then raise the landing gear. They'll ask about the order every time. Also, learn the maximum lengths and weights for doubles and triples on South Dakota roads — the state allows up to 110 feet on certain highways, but not on all.
Wind is a big deal here. The manual talks about reducing speed in high winds, but South Dakota drivers know that empty trailers are the worst. The test will give you scenarios about wind from the side and ask what you should do. Answer: slow down, don't steer into the wind, and consider dropping a trailer if it's too dangerous.
South Dakota DPS (Department of Public Safety) handles all CDL testing. You'll find testing sites in Pierre, Sioux Falls, Rapid City, Aberdeen, Watertown, and a few other regional offices. Appointments are strongly recommended — walk-ins are sometimes accepted but you might wait hours. The Doubles and Triples endorsement test costs $5 (separate from the $20 CLP fee). You need a valid Medical Examiner's Certificate before you take any written test.
The state follows federal guidelines but adds a few wrinkles. South Dakota allows double and triple trailers on the Interstate system and designated US highways (like US-212 and US-14). But you can't operate them on all state roads — the test might ask about restricted routes. Also, the state has specific chain requirements for combination vehicles during winter storms. Know when you must chain up.
You must hold a valid Class A CDL or be applying for one to get this endorsement. The Doubles and Triples test is the written knowledge test only — no skills test for this endorsement, but you'll need to demonstrate proficiency during your road test if you're getting your initial Class A.
About the South Dakota Doubles and Triples Test
South Dakota's wide-open spaces mean a lot of freight moves on double and triple trailers. You'll see them hauling grain to elevators near Watertown, livestock out of Winner, and fuel to the Bakken oilfields in the northwest corner. If you want to pull more than one trailer, you need the Doubles and Triples endorsement — it's separate from the basic Combination Vehicles test.
The test focuses on the unique physics of pulling two or three trailers. Things like off-tracking through tight turns (think of the grain elevator in Mitchell), the extra sway from crosswinds on I-90 between Wall and Rapid City, and how to couple and uncouple the dolly without getting pinched. South Dakota's wind can flip an empty double if you're not careful — the examiners know that.
The state DMV follows federal standards: 20 multiple-choice questions, 80% to pass. You'll take this test at the same time as your General Knowledge and Combination Vehicles tests at any SD DPS testing site — Pierre, Sioux Falls, Rapid City, or one of the regional offices. Bring your medical certificate and be ready for questions that go beyond the basics.
Topics Covered
Study Tips
South Dakota's Doubles and Triples test is more than memorizing steps. You need to understand why each step matters. For example, when you're coupling, the order of hooking air lines versus electrical lines isn't random — it's about safety. The examiners in Pierre will ask 'what happens if you do it backwards?' Know that.
Focus on the dolly. The converter dolly is where most mistakes happen. Practice the sequence: back under, lock the pintle hook, connect safety chains, hook air and electrical, then raise the landing gear. They'll ask about the order every time. Also, learn the maximum lengths and weights for doubles and triples on South Dakota roads — the state allows up to 110 feet on certain highways, but not on all.
Wind is a big deal here. The manual talks about reducing speed in high winds, but South Dakota drivers know that empty trailers are the worst. The test will give you scenarios about wind from the side and ask what you should do. Answer: slow down, don't steer into the wind, and consider dropping a trailer if it's too dangerous.
South Dakota Specific Information
South Dakota DPS (Department of Public Safety) handles all CDL testing. You'll find testing sites in Pierre, Sioux Falls, Rapid City, Aberdeen, Watertown, and a few other regional offices. Appointments are strongly recommended — walk-ins are sometimes accepted but you might wait hours. The Doubles and Triples endorsement test costs $5 (separate from the $20 CLP fee). You need a valid Medical Examiner's Certificate before you take any written test.
The state follows federal guidelines but adds a few wrinkles. South Dakota allows double and triple trailers on the Interstate system and designated US highways (like US-212 and US-14). But you can't operate them on all state roads — the test might ask about restricted routes. Also, the state has specific chain requirements for combination vehicles during winter storms. Know when you must chain up.
You must hold a valid Class A CDL or be applying for one to get this endorsement. The Doubles and Triples test is the written knowledge test only — no skills test for this endorsement, but you'll need to demonstrate proficiency during your road test if you're getting your initial Class A.