An early warning
It sounds like a word problem straight out of a school math book: If a car is traveling 55 mph and a tractor is traveling 15 mph, how long does it take for the car to make up the 400-foot distance between them?

The answer is 7 seconds-not a lot of time for the driver of the car to slow down, unless there is sufficient warning. The slow-moving vehicle (SMV) emblem, a fluorescent orange triangle with "retroreflective" borders, does just that. It warns approaching vehicles to slow down.

The SMV emblem is required by the Ohio Revised Code when moving "implements of husbandry" and farm machinery on public roadways. Implements of husbandry are vehicles designed and adapted exclusively for agricultural, horticultural, or livestock-raising operations. Additionally, SMV emblems are required on other specific vehicles, including horse-drawn vehicles.

SMV Characteristics

Must meet ASAE standards
Visible 500' to the rear
Readily identifiable both day and night
Condition of the emblem: clean, undamaged, not faded

Restrictions on SMV Use

Vehicle speed = 25 mph
Emblem not to be used when transporting equipment with motor vehicles,
(i.e. on a truck or trailer or at speeds > 25 mph)
Emblem not to be used on stationary objects such as fence posts, gates, etc.

History
In the late 1950s a 10-year retrospective study of fatal tractor accidents was conducted by Walter McClure and Ben Lamp, both of the Department of Agricultural Engineering at The Ohio State University (AEOSU), to understand their nature and causes. The research indicated a significant number of fatalities related to highway travel of slow-moving vehicles (SMVs). A research proposal written by Ken Harkness (AEOSU) and funded through the Automotive Safety Foundation (1961-62) further focused understanding of SMV accidents and resulted in the development of a unique SMV emblem. Early data estimated that 65 percent of the motor vehicle accidents involving SMVs were rear-end collisions. The Ohio State Highway Patrol, county sheriffs, and municipal police cooperated in the research by gathering detailed data on 708 SMV accidents.

In 1962, under the supervision of Ken Harkness, the design and testing of the SMV emblem was completed. A 1/16 scale highway simulator had been constructed to test human recognition rates of different shapes and colors mounted on simulated SMVs. After testing various designs, a triangular-shaped emblem with a 12-inch-high fluorescent orange center and three 1 3/4 inch wide reflective borders was determined to be the most effective design for day and night visual identification.

The Goodyear Rubber and Tire Company sponsored initial public exposure to the SMV emblem in 1962. An emblem mounted on the back of a farm wagon and towed by a Ford Tractor made a 3,689 mile trip from Portland, Maine to San Diego, California.

The first formal introduction of the SMV emblem was at a University of Iowa Invitational Safety Seminar in 1962. Carlton Zink of Deere and Company then became an avid promoter of the SMV emblem and played a major role in the adoption of the emblem by the American Society of Agricultural Engineers (ASAE).

In 1963 Novice G. Fawcett, President of The Ohio State University, dedicated the SMV emblem to the public. Also in 1963 the Agricultural Engineering Journal printed its first article with color illustrations about the SMV emblem. The National Safety Council promoted the adoption of the emblem and awarded a Certificate of Commendation to Ken Harkness.

In less than two years from the emblem¸s first date of availability, Nebraska, Michigan, Ohio, and Vermont adopted legislation requiring the emblem to be used on SMVs. Safety Leader Bill Stuckey, an Ohio Farm and Home Safety Committee member, spearheaded the adoption of the SMV emblem in Ohio. In 1967 the Canadian Standards Association (CSA) adopted the SMV emblem as a CSA Standard. In 1971 the SMV emblem became the first ASAE Standard to be adopted as a national standard by the American National Standards Institute (ANSI).

In recognition for the research and development of the SMV emblem, Ken Harkness was selected as a Charter Member of the Ohio Safety Hall of Fame in 1992.

In 1992 the American Society of Agricultural Engineers designated the development of the SMV emblem as an ASAE Historic Landmark.