South Dakota vs Wyoming Oversize Load Rules

What changes for an oversize load between South Dakota and Wyoming: legal height, pilot car triggers, height poles and travel hours.

I-90, reviewed October 2026

What changes at the South Dakota and Wyoming border

Legal height
Both states use the same legal height, 14 ft 0 in.
First pilot car
Wyoming requires a pilot car from 15 ft 0 in wide; South Dakota waits until 16 ft 0 in. A load between those widths needs an escort in Wyoming only.

Check one load against both states

South Dakota

  • Oversize permit required
  • No width escort

Wyoming

  • Oversize permit required
  • No width escort

11 ft 0 in wide, 14 ft 0 in tall. Length is not checked here.

Side by side

South Dakota and Wyoming oversize load rules compared
RuleSouth DakotaWyoming
Legal width8 ft 6 in8 ft 6 in
Legal height14 ft 0 in14 ft 0 in
Legal lengthLength limits are in SD Motor Carrier Handbook Table 7 (values not retrievable); load or retractable-extension overhang max 4 ft rear and 3 ft front.Single unit or semitrailer 60 ft; tractor with semitrailer/trailer combination 81 ft (48 ft semitrailer + 40 ft trailer max); any other combination 85 ft; maximum three single vehicles in a combination.
Gross weight80,000 lbs80,000 lbs
First pilot car at16 ft 0 in15 ft 0 in
Second pilot car atNot confirmedNot confirmed
Height pole atNot confirmedNot confirmed
Length escort atNot confirmed110 ft 0 in
Travel hoursOversize movement is generally daylight only. Night movement is allowed only on Interstates and only if no escort is required, width is 10 ft or less, height is 14 ft 6 in or less, a single unit is 45 ft or less, and a combination is 110 ft or less (other unit-length limits apply).Daylight hours only, except legal-height, permitted, signed and lighted: single units 60-75 ft, combinations under 100 ft where the single unit exceeds 60 ft, and loads up to 10 ft wide on Interstates may move at night.
WeekendsNo weekend restrictions; SD Truck Info states South Dakota has no weekend or holiday restrictions (daylight limits still apply).No general weekend restriction stated on the WHP commercial carrier page; holiday weekends are restricted for loads needing escorts.
Trip permit$15.00$20.00
Permit officeSouth Dakota Highway Patrol Permit Center / SDDOT (SD Truck Info)(307) 777-4376 (Wyoming Highway Patrol / WYDOT Commercial Carrier (Permits))

Go deeper

South Dakota and Wyoming FAQs

Do South Dakota and Wyoming require pilot cars at the same width?
Wyoming requires a pilot car from 15 ft 0 in wide; South Dakota waits until 16 ft 0 in. A load between those widths needs an escort in Wyoming only.
Is the legal truck height the same in South Dakota and Wyoming?
Both states use the same legal height, 14 ft 0 in.
Do I need a separate permit for each state between South Dakota and Wyoming?
Yes. Oversize and overweight permits are issued by each state, so a move through both needs a permit from South Dakota Highway Patrol Permit Center / SDDOT (SD Truck Info) and one from Wyoming Highway Patrol / WYDOT Commercial Carrier (Permits), each with its own route, hours and escort conditions.
Which travel hours apply in South Dakota and Wyoming?
South Dakota: Oversize movement is generally daylight only. Night movement is allowed only on Interstates and only if no escort is required, width is 10 ft or less, height is 14 ft 6 in or less, a single unit is 45 ft or less, and a combination is 110 ft or less (other unit-length limits apply). Wyoming: Daylight hours only, except legal-height, permitted, signed and lighted: single units 60-75 ft, combinations under 100 ft where the single unit exceeds 60 ft, and loads up to 10 ft wide on Interstates may move at night. The conditions printed on the permit control.

Compiled from each state's published permit rules, reviewed October 2026. Not legal advice; the conditions printed on your permit control.