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Farm Equipment Safety on Public Roads

Safe travels on roadways with agricultural equipment requires an extra degree of caution from those operating the equipment and those in other vehicles.

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Updated:

March 25, 2025

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Farm tractor with a Slow Moving Vehicle Emblem

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Overview

Most agricultural producers move production equipment on public roads for tillage, planting, harvesting, and marketing crops. Tractors and farming implements typically travel on roadways at speeds of less than 25 mph (40 km/hour), and drivers of motor vehicles might not be used to the braking times required to avoid a rear-end collision with farm equipment.

Greater visibility through lighting and marking is crucial to increase roadway safety because it provides increased sight distance for decision-making and stopping. The most common is the Slow Moving Vehicle Emblem (SMV), developed for tractors and towed equipment by the American Society of Agricultural and Biological Engineers (ASABE).

Slow Moving Vehicle Emblem

The SMV emblem is a highly reflective sign required on the back of all tractors, towed implements, and self-propelled implements used on public roads. What is most important with SMV emblems is that they make the equipment stand out or be more conspicuous so that others on the road can see you and slow down.

SMV and Pennsylvania Vehicle Code

The use of the SMV emblem is mandated in Pennsylvania by state law and outlined in the following Pennsylvania Vehicle Code:

#4529. Slow-Moving Vehicle Emblem

General rule—All implements of husbandry, commercial implements of husbandry, and special mobile equipment designed to operate at 25 miles per hour or less and all animal-drawn vehicles shall, when traveling on a highway, display on the rear of the vehicle a reflective slow moving vehicle emblem as specified in regulations of the Department. The use of the slow-moving vehicle emblem shall be in addition to any other lighting devices or equipment required by this title.
Limitations on use or display—No person shall use or display the slow-moving vehicle emblem except as provided in this section, nor shall any person display the emblem on a vehicle traveling at a speed in excess of 25 miles per hour.
Towed vehicles—The emblem shall be required to be displayed on a slow-moving vehicle that is being towed on a highway unless the towing vehicle displays the emblem in such a manner as to be clearly visible from the rear.

The term "highway" as used in the Code is officially defined as "the entire width between the boundary lines of every way publicly maintained when any part thereof is open to public use for purposes of vehicular traffic."

Characteristics of the SMV Emblem and Maintenance

Required characteristics of the SMV emblem.

Agricultural producers are responsible for maintaining SMV emblems and replacing them when necessary. Fluorescent and reflective material aids with daytime and nighttime visibility. But keep in mind that the materials don't last forever. For example, the orange fluorescent center portion of the SMV emblem will fade and turn color over time, changing from orange to yellow, pink, or white. Maintaining fresh emblems with maximum fluorescence and wiping off dirt makes a big difference, especially in the early morning or late evening. Another thing to know is that the retroreflective border material used in the manufacturing of new SMV emblems is different than older SMVs and can now be detected as far as a mile away, compared to only a few hundred feet for the older SMVs.

Placement of an SMV

The correct placement of the SMV is vital for it to be effective. Use the following guidelines when attaching an SMV emblem:

With the triangle pointing upward, place the SMV emblem at the rear center or left rear of center of the vehicle or implement.
Center the SMV emblem horizontally on the vehicle.
The triangle's bottom edge should be between 2 and 10 feet above the ground.

SMV and light on the back of equipment — Lighting and marking on farm machinery

Since the SMV emblem is used to increase the visibility of agricultural tractors and machinery, you should not use it for any other purpose. You could decrease its effectiveness by using it to mark things such as a driveway or mailbox.

Speed Indicator Symbol

Tractors and agricultural equipment are considered slow-moving vehicles. However, some newer tractors can travel over 25 mph, which is the maximum speed limit when using the SMV emblem. States continue to discuss using the SMV symbol on these high-speed tractors. In response, ASABE revised the S276 "Slow Moving Vehicle Identification Emblem (SMV) Emblem)" and S279.16 "Lighting and Marking of Agricultural Equipment on Highways" to standardize the use of a speed indicator symbol (SIS) on the rear of higher speed tractors that indicates their maximum speed.

Reflective Tape and Lighting

The 2012 Moving Ahead for Progress in the 21st Century Act established lighting and marking standards for agricultural equipment operated on public roads. These standards are based on the American Society for Agricultural and Biological Engineers (ASAE). See Table 1 for a summary of the lighting and marking of agricultural equipment.

Table 1. Surface Transportation Legislation for Lighting and Marking of Agricultural Equipment
Item	Federal recommendations based on the standards from the ASAE	PA Requirements
Headlights	2 white headlights Mounted on either side of vehicle centerline at same height	Same as ASAE recommendation¹
Taillights	2 red taillights Symmetrically mounted to rear between 1.3' to 12' and no greater than 5' to left and right of machine center.	One mounted at each side on rear¹
Hazard Flashers	Minimum of 2 amber flashers Symmetrically mounted to rear between 1.3' to 12' and symmetrically spaced as widely apart as practicable to be visible from front and rear (60 - 85 flashes/min)	Two if double-faced with amber to front and red to rear Four if single faced - amber on front corners and red of rear¹
Turn Indicators	2 amber or red turn indicators Mounted 1.3' to 12' high and symmetrically spaced as widely apart as practicable to be visible from front and rear.	Not required
SMV Emblem	1 fluorescent red-orange triangle for daylight with red retroreflective border for nightime. Mounted on rear center or rear left for maximum visibility of 1,000 feet day or night, 2' to 10' above ground.	All implements of husbandry designed to operate at 25 mph or less shall always display the SMV on rear of vehicle on highways.
Reflectors	2 red reflectors on rear of machine 2 yellow reflectors on front of machine May be either part of tail lamp lens or made with conspicuous material. Size to be 2" wide by 4.5" long for machines <6.7' wide. Size to increase to 2" by 9" for wider machines which are >6.7'wide.	One red reflext reflector or reflective tape at rear on each side. One amber reflex reflector or reflective tape at front on each side with size or reflector to be 3 square inches or more.¹
Rotating Beacons	Not required	One flashing or revolving yellow light or strobe light
Conspicuous material to better define size and to increase visibility (machinery or towed equipment)	Red retroreflective and red-orange fluorescent material to be visible to rear Mount on rear corners within 25" of left and right outer corners of the machine. Distance between materials should not exceed 6'. Yellow retroreflective material to be visible to front.² Mounting to be within 16" of outside corners.	SMV only

¹ between sunset and sunrise and during reduced visibility

² for trailing equipment > 16.4' behind hitch point, display amber/yellow reflectors spaced < 16.4' apart on sides.

Note: Additional lighting and implement accessories typically require a 7-terminal receptacle.

References

American Society of Agricultural and Biological Engineers, 2010, ANSI/ASAE 276.7 W/Corr. 1. Slow Moving Vehicle Identification Emblem (SMV Emblem). St. Joseph, MI. Retrieved from elibrary at ASABE
American Society of Agricultural and Biological Engineers, 2013, ANSI/ASAE 279.17. Lighting and Marking of Agricultural Equipment on Highways. St. Joseph, MI. Retrieved from elibrary at ASABE
Agricultural Equipment on Public Roads (2009) North Central Education/Extension Research Activity Committee 197. Cooperative State Research, Education, and Extension Service. United State Department of Agriculture.
U.S. Congress. House of Representatives. Surface Transportation of 2012. H.R. 112th Congress, 2nd Session, 2012. Retrieved September 14, 2012 from House Bill HR4348(pdf).
Fact sheet: Implements of husbandry. (2018) Pennsylvania Department of Transportation.
Farm vehicles (n.d.) Pennsylvania Department of Transportation.

Original authors: Dennis J. Murphy, retired Professor Emeritus, Agricultural Safety and Health.

Article updated by Florence Becot, Nationwide Early Career Professor of Agricultural Safety and Health and Linda Fetzer, Extension Program Specialist.

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