Harvest Season Safety: The Importance of Slow-Moving Vehicle Signs

Did you know 19% of Americans live in rural areas, but make up for 45% of traffic crash fatalities? *

As Michigan’s harvest season gets underway, rural roads become shared spaces between passenger vehicles and farm equipment. Tractors, wagons, and combines are essential to the season — but they also pose unique risks when traveling at low speeds on public roads. That’s why slow-moving vehicle (SMV) signs are more than just a legal requirement — they’re a critical safety tool.

What Is an SMV Sign?

An SMV sign is the bright orange triangle mounted on the rear of vehicles that travel under 25 mph. It alerts other drivers to slow down and approach with caution. In Michigan, SMV signs are required by law on farm equipment, trailers, and other slow-moving vehicles operating on public roads.

Why It Matters During Harvest:

• Visibility Saves Lives: As daylight hours shorten and dust from fields increases, visibility becomes a challenge. A clean, properly mounted SMV sign helps prevent rear-end collisions and gives drivers time to react.
• Legal Compliance: Michigan law mandates SMV signs on qualifying vehicles. Failing to display one can result in fines — and worse, liability in the event of an accident.
• Community Awareness: Harvest season brings more equipment onto the roads. Educating local drivers about SMV signs helps build patience and understanding, especially in areas with heavy agricultural traffic.

Tips for rural drivers:

• Farm machinery can unexpectedly turn onto a public road from a field or driveway. It is important for everyone’s safety to have patience and share the road.
• Machinery that is half on the road and half on the shoulder may suddenly move completely onto the road. Machinery may take up more than one lane to avoid obstacles such as road signs and mailboxes.
• Farm machinery travels slower than normal traffic, often at speeds of 25 miles per hour or less. Motorists must quickly identify farm equipment and slow down immediately to avoid rear-end crashes. A car going 55 mph will require 300 feet of braking distance — that's as long as a football field — to avoid rear-ending farm equipment traveling 15 mph. That means only about five seconds to close the gap.
• Farmers do their best to keep equipment off public roads and away from high-traffic areas, and most will pull over to allow drivers to safely pass. But sometimes it's not so easy; when road shoulders are soft or steep, pulling over can pose the risk of tipping.

Before passing farm machinery:

• Check to be sure that machinery is not turning left. Look for left turn lights or hand signals. If the machinery slows and pulls toward the right side of the road, the operator is likely preparing to make a wide left turn. Likewise, sometimes to make a right turn with wide equipment, the driver must fade to the left.
• Determine if the road is wide enough for you and the machinery to safely share.
• Look for roadside obstacles such as mailboxes, bridges, or road signs that may cause the machinery to move to the center of the road.
• Be sure there is adequate distance for you to safely pass.

Best Practices for Farmers

• Inspect SMV signs regularly for fading, damage, or dirt.
• Mount signs at eye level, centered on the rear of the vehicle.
• Replace any signs that are cracked, sun-bleached, or missing reflectivity.
• Use additional lighting or reflective tape for nighttime or low-light travel.
• Slow moving vehicle signs are required on every implement of hus­bandry, farm tractor, modified agricultural vehicle, special mobile equipment, or any vehicle that has a maximum speed of 25 miles per hour.

Please practice caution and patience while driving during harvest season. 

Sources: 

9510-Rural-Road-Safety-brochure.pdf (michigan.gov)

Michigan Farm News