Agricultural Equipment on Public Roads

  • Committee on Agricultural Safety and Health Research and Ext,

TABLE OF CONTENTS

Preface, Acknowledgments, Executive Summary
1.0 Introduction
2.0 The Rural/Urban Traffic Interface
3.0 Federal and State Regulations
4.0 Higher Speed Tractors
5.0 Transportation of Workers on Public Roadways with Farm Equipment
6.0 Suggestions for the Future
7.0 References
8.0 List of Committee on Agricultural Safety and Health Research and Extension Members

3.0 FEDERAL AND STATE REGULATIONS

3.1 PROBLEMS IDENTIFIED BY US:

  • Guidance relating to farm equipment operation on roadways and lighting and marking for it provided by the national Uniform Vehicle Code is inadequate and not embraced in state regulations.
  • There is a bewildering array of state vehicle code regulations governing lighting and marking of agricultural equipment on public roads.
  • These state vehicle code regulations have not kept pace with advances in lighting and marking made by the voluntary consensus standards process implemented by farm equipment manufacturers.
  • Tractors have historically been identified as moving 25 mph (40 km/h) or less but some new tractors may now travel up to 45 mph (72 km/h).
  • States are inconsistent in how they address young operators of agricultural equipment on public roads.

3.2 WHAT DO WE KNOW ABOUT THESE PROBLEMS?

3.2.1 UNIFORM VEHICLE CODE AND LIGHTING AND MARKING OF AGRICULTURAL EQUIPMENT.

Perhaps the most fundamental issue surrounding the requirement of lighting and marking of agricultural equipment is directed towards the confusion of how state laws define a slow-moving vehicle or implement of husbandry. Some states define a slow moving vehicle by its maximum speed; and some define it by use or vehicle type (Glascock et al., 1995). This variation in legal definition allows for a wide variety of accepted lighting and marking configurations, and perhaps is a contributing factor to the motoring public’s lack of recognition of an agricultural slow moving vehicle.

Legislation dealing with farm tractors and agricultural equipment generally reflects how such machines, historically, were used in the field and spent minimal time on the road. In the United States each state has its own traffic code, although most of the rules of the road are similar for the purpose of uniformity, given that all states grant reciprocal driving privileges (and penalties) to each others' licensed drivers. Ironically, there is a “Uniform Vehicle Code” (UVC) which is a privately prepared set of suggested model United States traffic codes prepared by the National Committee on Uniform Traffic Laws and Ordinances (NCUTLO).

Legislation dealing with farm tractors and agricultural equipment generally reflects how such machines, historically, were used in the field and spent minimal time on the road. In the United States each state has its own traffic code, although most of the rules of the road are similar for the purpose of uniformity, given that all states grant reciprocal driving privileges (and penalties) to each others' licensed drivers. Ironically, there is a “Uniform Vehicle Code” (UVC) which is a privately prepared set of suggested model United States traffic codes prepared by the National Committee on Uniform Traffic Laws and Ordinances (NCUTLO).

The NCUTLO is a private, non-profit membership organization dedicated to providing uniformity of traffic laws and regulations through the timely dissemination of information and model legislation on traffic safety issues. This committee adopted its first code in July, 1926. The Code consisted of four acts: vehicle registration; antitheft; operators’ and chauffeurs’ licensing; and a fourth part, regulating the operation of vehicles on highways. this section prescribed rules of the road, speed limits, rules against reckless driving or driving while intoxicated, and those governing size, weight, and equipment of vehicles (Barber, 1927).

Some states adopt selected portions of the code as written by the NCUTLO or with modifications, while other states create their own versions. Initially, both the regulations suggested by the UVC for lighting of agricultural equipment on public roads and provisions provided by manufacturers on agricultural equipment moved forward, incrementally, evolving roughly in sync into the middle 1950s. Thereafter, both industry consensus standards and what manufacturers provided improved regularly. But neither the model UVC nor the requirements passed by state codes kept pace. For example, at the time of the U.S. Department of Transportation’s January 1971 “Agricultural Tractor Safety on Public Roads and Farms” report to Congress, only one state had laws conforming in all respects with the UVC and only twelve were in substantial agreement with the UVC with regard to agricultural tractors and self-propelled machines. Furthermore, one-third of all states still required only the minimal lighting devices that were considered feasible four decades earlier.

The U.S. Department of Transportation’s report to Congress concluded that if immediate corrective action was necessary, enabling legislation at the state level based on the UVC was the mechanism recommended to improve illumination and turn signaling. Furthermore, such legislation should be developed to address retrofitting equipment since it would otherwise take an estimated 30 years before new lighting presentations would dominate if they were introduced solely on new equipment (U.S. DOT, 1971). The report did not include antique equipment, a category of vehicle that is much more popular and visible today than in 1971.

The 2000 edition of the NCUTLO UVC offers that, after a specified date left to State discretion, every new tractor and self-propelled machine be equipped with at least two headlights, at least one red rear light mounted as far left as practicable, and two red rear reflectors (NCUTLO, 2000). The UVC 2000 also calls for every agricultural tractor and self-propelled machine to be fitted with hazard warning lights visible to the front and to the rear, whenever on a roadway, to warn operators of other vehicles about the presence of a special traffic hazard requiring unusual care. Moreover, every such vehicle is to be equipped with hazard warning lights required for that vehicle by applicable standards of the U.S. Department of Transportation at the time of its manufacture. However, no such U.S. Department of Transportation standards have been found.

For every combination of an agricultural tractor and towed implement, according to UVC 2000, the tractor is to be equipped as described in the preceding two paragraphs and the towed implement equipped as follows. If the towed unit extends over 4 feet (1.2 meters) to the rear of the tractor or obscures any light, the implement shall be equipped with at least one red rear light mounted as far left as practicable and at least two red rear reflectors. If the towed implement extends over 4 feet (1.2 meters) to the left of the tractor’s centerline, the implement shall be equipped with an amber reflector to the front as far left as practicable. If the towed implement or its load obscures either of the flashing warning lights of the tractor, the towed implement shall be equipped with hazard warning lights as prescribed for the tractor, along with two red rear reflectors positioned to delineate the combination’s extremes of width. In some instances reflectors are substituted for lights.

3.2.2 STATE VEHICLE CODES.

Additional comprehensive reviews of state highway regulations and lighting and marking for agricultural equipment were published in the early 1990s. For example, Becker (1991) contacted all 50 state highway commissioners or directors to ask about highway safety laws for agricultural vehicles, equipment and personnel. Eicher et al. (1995) and Glascock et al. (1995) have reported on their reviews of all 50 states for regulations concerning lighting and marking of agricultural equipment on public roads. Based on an earlier survey of state agencies (McFarland, 1965), Eicher et al. (1995) developed a new set of 29 questions regarding agricultural road safety issues. From the Eicher et al. (1995) study, Glascock et al. (1995) compiled the questions and answers to 15 questions relevant to front and rear lighting patterns. These questions and answers provided a summary of state law requirements. The questions and answers, as presented by Glascock et al. (1995), are listed below and in Table 2, respectively.

  1. How many headlights are required on tractors and self-propelled agricultural equipment (SPAE)?

  2. Are tractors and SPAE headlights required for day use?

  3. Headlights must be visible at all times specified from a distance of no less than?

  4. How many taillights are required for day use on tractors and SPAE?

  5. Are taillights required for day use on tractors and SPAE?

  6. The taillights of tractors and SPAE must be visible, at all times specified, from a distance no less than?

  7. What is the required color of the taillights? (R=Red; A=Amber)

  8. Are amber flashing lights required/permitted? (NP=Not Permitted; NR=Not Required; R=Required)
  1. Are turn signals required on tractors and SPAE?

  2. Are SMV emblems required on tractors and SPAE?

  3. Are white lights permitted to show to the rear on tractors and SPAE?

  4. Does towed equipment and implements of husbandry need to have taillights/flashers/reflectors if the taillights/flashers/reflectors on the towing vehicle are visible?
  1. Are amber flashing lights on implements of husbandry required/permitted?
  1. Are turn signals required on implements of husbandry?
  1. Are tractors, SPAE, or implements of husbandry required to display a warning flag?

Table 2. A compendium of state laws as of 1995 pertaining to the lighting and marking of agricultural equipment .

Question Numbers and Answers
State
1
2
3m
4
5
6m
7
8
12
13
14
15
19
21
25
Alabama
1
No
152
1
No
152
Red
NR
No
Yes
nic
Yes
NR
nic
No
Alaska
nic
nic
nic
nic
nic
nic
nic
nic
No
Yes
nic
nic
nic
nic
Yes

Arizona

1

No

152

1

No

152

Red

NR

No

No

NIC

No

NR

NIC

No

Arkansas

2a

No

152

2a,b

No

152

Red

NR

No

No

Yes

Yes

NR

No

No

California

2

No

61

1

No

152

Red

NR

No

Yes

No

NIC

NR

No

Yes

Colorado

2a

No

61

1

No

152

Red

NR

No

Yes

NIC

Yes

NR

No

No

Conn.

2

No

61

2

No

305

Red

NR

No

No

NIC

Yes

NR

No

No

Delaware

1

No

152

2b

No

152

Red

NR

No

No

NIC

NIC

NR

No

No

Florida

2

No

61

1

No

305

Red

R

No

Yes

NIC

Yes

NR

No

No

Georgia

2

No

152

1

No

152

Red

NIC

No

Yes

NIC

Yes

NR

No

No

Hawaii

2

No

61

2

No

61

Red

NR

No

Yes

NIC

No

NIC

NIC

Yes

Idaho

2a,e

No

152

2a,b,e

No

152

Red

R

No

Yes

NIC

No

NR

No

No

Illinois

2

No

305

2

No

305

Red

R

No

Yes

NIC

NIC

R

No

No

Indiana

2a,e

No

152

2a,b

No

152

Red

R

No

Yes

NIC

Yes

R

No

No

Iowa

2

No

152

1

No

152

Red

R

No

Yes

No

Yes

R

No

No

Kansas

2

No

61

1

No

305

Red

R

No

Yes

NIC

Yes

R

No

No

Kentucky

1

Yes

31

1

Yes

31

W/R

NR

No

Yes

Yes

No

NR

No

No

Louisiana

2a

No

152

1j

No

152

Red

NR

No

Yes

NIC

Yes

NR

No

No

Maine

2

No

15

1

No

31

Red

NIC

NIC

No

NIC

NIC

NIC

NIC

NIC

Maryland

2

No

61

2

No

305

Red

NR

No

Yes

No

Yes

NR

No

No

Mass.

1

No

NIC

1

No

NIC

Red

NR

No

Yes

No

NIC

NR

No

NIC

Michigan

1

No

152

1

No

92

Red

NR

No

Yes

NIC

Yes

NR

No

No

Minnesota

1

No

152

1e

No

152

Red

NR

No

Yes

No

Yes

NR

No

No

Mississippi

2

No

152

1

No

152

Red

NR

No

Yes

NIC

Yes

NR

No

No

Missouri

1

No

152

1

No

152

Red

NR

No

Yes

NIC

NIC

NP

NIC

NIC

Montana

2a,e

No

152

2b

No

152

Red

NR

No

Yes

NIC

Yes

NR

No

No

Nebraska

2

No

152

1

No

152

Red

NR

No

Yes

NIC

No

NR

No

No

Nevada

2

No

152

1

No

305

Red

R

No

Yes

NIC

Yes

NR

No

No

New Hamp.

2

No

305

1

No

305

Red

NR

No

Yes

No

Yes

NR

No

No

New Jersey

1

No

152

1

No

152

Red

NR

No

No

NIC

Yes

NR

No

No

New Mexico

2a

No

152

1

No

152

Red

NR

No

Yes

No

Yes

NR

No

No

New York

2

No

305

1

No

152

Red

NR

No

Yes

No

NIC

NR

No

No

N. Carolina

1

No

152

1

No

152

Red

NR

No

No

No

NIC

NR

No

No

N. Dakota

2a

No

305

1

No

305

Red

NR

No

No

No

Yes

NR

No

No

Ohio

1

No

305

2b

No

305

Red

NR

No

Yes

No

No

NR

No

No

Oklahoma

2a,e

No

152

2a,b,e

No

152

Red

NR

No

Yes

NIC

Yes

NR

No

No

Oregon

2

No

152

1

No

NIC

NIC

NR

No

Yes

NIC

NIC

NR

No

No

Penn.

2

No

305

2

No

NIC

Red

R

No

Yes

No

No

NR

No

No

Rhode Isl.

2

No

23

1

No

152

Red

NP

No

Yes

NIC

Yes

NP

No

No

S. Carolina

2

No

61

1

No

152

Red

NR

No

No

No

Yes

NR

No

No

S. Dakota

1

No

152

2

No

305

Red

NP

 No

Yes

Yes

No

NP

No

No

Tennessee

1e

No

152

1e

No

152

Red

NIC

No

Yes

No

Yes

NIC

No

No

Texas

2

No

31

1e

No

305

Red

R

No

Yes

NIC

Yes

Rf

No

No

Utah

2

No

305

1e

No

305

Red

R

No

Yes

NIC

Yes

Rf

No

No

Vermont

2

No

46

1

No

NIC

Red

NIC

No

Yes

NIC

Yes

NR

No

No

(a) Only one (1) is required when tractor is not equipped with electrical system; (b) Two (2) reflectors and one (1) taillight may be used instead; (e) One (1) lamp or reflector must be placed as far as left as practicable. (j) Two are required only on self-propelled agricultural equipment. NIC: not in code. Table reprinted with permission from ASABE.

This type of study has not been replicated. It is shown here as an example of the types of studies that are needed on an ongoing basis.

3.2.3 SLOW MOVING VEHICLE EMBLEM.

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, to understand their nature and causes (McClure and Lamp, 1961). The research indicated a significant number of fatalities related to highway travel of slow-moving vehicles. A research proposal written by Ken Harkness, also an agricultural engineer at Ohio State University, and funded through the Automotive Safety Foundation (1961-62) further focused understanding of slow moving vehicle collisions and resulted in the development of a unique SMV emblem. Early data estimated that 65 percent of the motor vehicle crashes involving slow moving farm equipment were rear-end collisions. The Ohio State Highway Patrol, county sheriffs, and municipal police cooperated in the research by gathering detailed data on 708 farm equipment vs. motor vehicle crashes (Harkness and Stuckey, 1962).

In 1962, under the supervision of Ken Harkness, the design and testing of the SMV emblem was completed. A 1/16th scale highway simulator had been constructed to test human recognition rates of different shapes and colors mounted on simulated slow moving vehicles. After testing various designs, a triangular-shaped emblem with a 12 inch (30 centimeters) high fluorescent orange center and three 1.75 inch (4.4 centimeters) wide reflective borders was determined to be the most effective design for day and night visual identification. The emblem quickly became known as the SMV (slow moving vehicle) emblem.

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 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 as a recommendation by the ASAE in 19642 as R276 “Slow Moving Vehicle Identification Emblem (SMV Emblem)”. Among other things, this standard established the definition of a slow moving vehicle as agricultural machinery or implements of husbandry that traveled at a speed of 25 mph (40 km/h) or less.

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 (Harkness, 1963). 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 slow moving vehicles. 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 1992, the American Society of Agricultural Engineers designated the development of the SMV emblem as an ASAE Historic Landmark.

The SMV emblem standard was significantly improved when the standard was revised in 1997 with version S276.5. This standard adopted the use of new, more advanced, retro-reflective and fluorescent material available on the market. Emblems that meet this standard are visible at about 1,000 feet (305 meters) whereas emblems meeting older versions of the standard are visible to the driving public between 400 to 600 feet (122 to183 meters). In addition, degradation of the visibility characteristics of the emblem is significantly reduced under the Florida sunlight test. Emblems meeting the S276.5 standard generally last about twice as long as the older material before fading below levels set by the standard. Since this significant revision of the standard, most states have adopted the newer version of the standard for slow moving vehicles manufactured since about 2001. Illinois is the only known state that requires all implements of husbandry operated on public roadways to display an SMV emblem, new or old, that meets ASAE S276.5 or greater. Most manufacturers have complied with the new standards since they were adopted by ASABE.

Most farm equipment on farms have an SMV emblem on it. For example, in a survey of Pennsylvania Farmers Association members (now known as Pennsylvania Farm Bureau), farm operators indicated that 77-85% of their most frequently operated tractor was equipped with an SMV emblem (Ambe,1994). Hanna et al. (1997) found that a large majority of tractors and wagons (70 to 87%) in lines at a sample of commercial grain elevators in Iowa were equipped with an SMV emblem. However, the condition or quality of the SMV may be more problematic.

Anecdotally, many farm safety professionals routinely observe SMV emblems that are severely faded, bent, cracked or on upside down. West and May (1998) found in their inspections of tractors and PTO-powered implements at auction sites in New York state that 80.7% of tractors and 62.7% of PTO-powered implements had missing or defective SMV emblems. The researchers did not distinguish between “missing” or “defective’, nor did they define the term defective. It is reasonable to presume that the term “defective” included badly faded and bent and cracked emblems. Some support for the assumption that many, if not most, of these deficiencies were faded, bent or cracked emblems comes from a study by Murphy et al. (1998). In this study, trained farm safety auditors in Central Pennsylvania considered the quality of SMVs on a cohort of cooperating farm operators’ three most used tractors. Only 32.5% of the 193 SMV emblems were found to be “on, properly placed and bright in color”.

Despite the longevity and use of the SMV emblem by farmers, there is a significant problem with recognition of the SMV emblem by the general driving public. Garvey (2003) reported that, while older drivers understood the meaning of the emblem better than their younger counterparts, overall emblem comprehension was fewer than 30%. According to Garvey, the improvement of the SMV emblem’s comprehensibility must be addressed through more consistent and accurate motorist education, increased enforcement of state motor vehicle codes (particularly against illegal use of the emblem to mark fixed objects), and emblem modification to make it more iconic in nature or at least to ensure that it appears the same to approaching drivers in daylight and at night.

Lehtola (2007) confirmed that many states do not provide any information on the emblem in the educational materials provided to those in drivers’ education programs or for those studying on their own to take their state driver’s test. Lehtola found that in many states there is no mention of the hazards associated with sharing the road with farm equipment in driver’s education manuals, and that the training drivers receive regarding recognition of SMV emblems and farm equipment is inconsistent. Driver’s manuals in nine states (several being highly agricultural states) had no mention of farm equipment or slow-moving vehicles at all. This is a substantial finding because for SMV emblems to be a potential factor in avoiding collisions, it requires that a good SMV emblem be visible to the rear of farm equipment and other drivers must know what the emblem represents.

Another issue is how well SMV emblem regulations are enforced. There is concern that many counties and states are not adequately enforcing the regulations they have. This was brought out in a study by West and May (1998) who conducted a survey of equipment at New York farm auctions to measure the amount of safety defects on equipment sold. Based on ASAE standards, SMV signs were defective or absent on 60- 80% of equipment.

Finally, a question can be raised of the SMV emblem’s relevance to today’s agricultural equipment. When the SMV emblem was initially devised and tested during the early 1960s, most tractors did not travel faster than 20 mph (30 km/h) and did not tow equipment much wider than the tractor itself. The only self-propelled equipment found on public roads were combines and swathers and they typically moved even slower than tractors. Nor was miss-use of the SMV emblem as common as it is today (see the section below).

3.2.4 MISUSE OF THE SMV EMBLEM.

A continuing problem in most states is the misuse of SMV emblems. They can often be found marking the entrance to driveways, mailboxes, gates, and on vehicles they are not intended to be used on. Most states have laws that do not allow the misuse of the emblem and allow for the perpetrators to be fined. For example, in Illinois anyone that uses an SMV emblem on any vehicle or structure other than those vehicles classified as slow moving vehicles in their statutes can be fined up to $75. However, enforcement is generally very lax or non-existent. Most law enforcement officers are either not familiar with this aspect of their respective state motor vehicle regulations or they choose not to enforce the law for a variety of reasons.

While there has been no known research conducted to verify what affect misuse of the emblem has on collision risk with farm equipment, it is likely there are negative impacts. For instance, because the emblem is no longer a unique identifier of slow moving agricultural equipment, faster traveling motorists may not be as likely to slow down as quickly as they approach from the rear. As explained earlier, the potential hazard of this situation becomes apparent when considering the rate of closure between vehicles traveling at a posted speed and slow-moving vehicles.

3.2.5 SPEED INDICATOR SYMBOL (SIS).

Currently, tractors and agricultural trailers are classified as slow moving vehicles. But as tractors begin to rival the speeds of trucks, the current legal classifications may need to be revised to either change the definition of a slow moving vehicle or exempt tractors that can operate at 40 mph (64 km/h) and faster. Iowa lawmakers have already begun to wrestle with these issues. In 1999, the state changed the speed classification for SMVs from 25 to 35 mph (40 to 56 km/h) to keep faster tractors covered under the law.

Ohio is one of the country’s leaders in the number of high-speed tractors traveling the roadways. According to the Ohio Farm Bureau, two counties in Ohio have the highest concentration of high-speed tractors in the United States. Speeding citations have been issued to tractor operators operating at speeds over 25 mph (40 km/h) because the current law in Ohio requires that tractors must remain at 25 mph (40 km/h) or less and display a Slow Moving Vehicle (SMV) emblem. One problem Ohio lawmakers recognized was that there were no legal signs available to place on the tractors that would warn other drivers of the vehicle’s presence on the road. It was illegal to place the large orange slow moving vehicle (SMV) emblem on the tractors because they are capable of going over 25 mph (40 km/h).

During the same time period that the Ohio State Highway Patrol was issuing tickets because of higher speed tractors, the American Society of Agricultural and Biological Engineers was in the process of adopting (in 2005) Standard S584 “Agricultural Equipment: Speed Identification Symbol (SIS)”. The scope of this standard is primarily directed to identifying farm machinery that has been designed in its original equipment configuration for specified ground speeds greater than 25 mph (40 km/h). Because of the obvious connections, S276 “Slow Moving Vehicle Identification Emblem (SMV Emblem)” and S279 “Lighting and Marking of Agricultural Equipment on Highways” were revised to include the SIS on higher speed tractors in 2006.

Ohio legislation, enacted in October 2007, permits any unit of farm machinery that is designed by its manufacturer to operate at a speed greater than 25 mph (40 km/h) to do so as long as the unit displays both an SMV emblem and the Speed Identification Symbol (ASAE Standard 584.1) and that the vehicle does not exceed this documented speed (Ohio Revised Code, 2007). For towed implements, legislation requires both SMV and SIS emblems be displayed, and that the implement's SIS match the SIS on the tractor.

This legislation requires the operator to have documentation of manufacturer’s stated maximum speed of the vehicle, and maintain reasonable control while operating the vehicle on roadways. In addition, the operator of a unit of higher speed farm machinery who wishes to travel on a public street or road faster than 25 mph (40 km/h) must have a valid driver's or commercial driver's license.

A flaw in this legislation is that it requires the two SIS emblems (on the tractor and implement) to match. This may result in either: (1) operator citations unjustified from a safety perspective; or (2) encouraging operators to apply SIS emblems inappropriately to implements not rated for that speed, causing potentially unsafe situations.

The first scenario, citations that are unjustified from a safety perspective, can occur when an implement with a given SIS emblem (as applied by the implement manufacturer) is pulled by a tractor with either a lower SIS emblem or none at all. The SIS emblem represents an official manufacturer's rating of the highest safe speed at which an implement can be pulled; there is nothing unsafe about an implement being pulled by a tractor with a lower SIS rating. Furthermore, tractors without SIS emblems were not manufactured to travel fast enough to merit an SIS emblem, and thus would also have a top speed lower than that of the implement with the SIS emblem. Since only a small percent of tractors currently in use have SIS emblems, it is quite likely that new implements with an SIS emblem applied by the manufacturer will be pulled by tractors without an SIS rating, which is perfectly safe. The law, as is, could actually encourage tractor operators to apply SIS emblems to tractors that cannot travel at that speed simply to avoid being cited.

The second scenario, inappropriate application of SIS emblems to implements not rated for that speed, could result when an operator of a tractor with an SIS emblem must pull an implement without an SIS emblem, i.e., an implement that has not been rated for a speed above 25 miles per hour (the speed above which an SIS emblem is required). To be safe, the tractor operator should not pull the implement faster than 25 mph: to pull it faster when it has not been rated for a higher speed risks an unsafe situation. But to avoid citations, operators might apply their own SIS emblems to the implement, since law enforcement is only looking to see that they match. This inappropriate application most likely will result in the implement being pulled at a speed for which it was not rated, but more importantly, gives the false impression to others that the implement was tested and rated by the manufacturer, especially future purchasers of such implements on the used equipment market. The SIS emblem must only represent manufacturers' official ratings, so an inappropriately applied emblem could result in the second owner towing the implement at unrated speeds and also potentially cause liability for the person who originally and inappropriately applied the emblem.

3.2.6 VOLUNTARY CONSENSUS STANDARDS.

ASABE, the American Society of Agricultural and Biological Engineers (formerly American Society of Agricultural Engineers, ASAE) is a technical society and the recognized standards developing organization for agricultural field and farmstead equipment in North America. ASABE standards are consensus documents developed and adopted to meet standardization needs within the scope of the Society; principally agricultural field equipment, farmstead equipment, structures, soil and water resource management, turf and landscape equipment, forest engineering, food and process engineering, electric power applications, plant and animal environment, and waste management (ASABE, 2007). ASABE Standards, Engineering Practices, and Data initially approved prior to the society name change in July of 2005 are designated as ‘ASAE’, regardless of the revision approval date. Newly developed Standards, Engineering Practices and Data approved after July of 2005 are designated as ‘ASABE’.

ASAE Standards, Engineering Practices, and Data are informational and advisory only. Use of these standards by anyone engaged in industry or trade is entirely voluntary and conformity does not ensure compliance with applicable ordinances, laws, and/or regulations. There were various forms and forums, ad hoc recommendations and guidance for agricultural equipment lighting prior to the 1950’s (S Cedarquist, private conversation, December, 2007). The first published compendium of ASAE standards was in 1954 (Agricultural Engineers Yearbook, 1954). It included a standard, ASAE S213, “Safety Lighting for Combinations of Farm Tractors and Implements”. The preface to that standard states:

“Act V, Section 137c, Uniform Act Regulating Traffic on Highways, revised and approved by National Committee on Uniform Traffic Laws and Ordinances, 1952, established regulations for safety lighting of farm tractors and implements when transported on the highway at night. Specifications essential to conformity with these regulations were accordingly developed by the Advisory Engineering Committee of the Farm Equipment Institute, and were adopted February, 1954, as an official standard of the American Society of Agricultural Engineers.”

The Farm Equipment Institute was the former name of the industry trade association for manufacturers of farm equipment. Its name, scope, and functions have changed over time but somewhat similar work continues within the current Association of Equipment Manufacturers (AEM) (AEM, 2007).

The 1954 ASAE safety lighting standard called for tractor manufacturers to provide an SAE (Society of Automotive Engineers) standard electrical connector socket. This outlet provided power to a safety lamp, showing red to the rear and amber to the front, which tractor manufacturers were to “make available”. It called for a means for the lamp to be mounted on the tractor, or optionally at the left extremity of the towed implement and be energized through a 22-foot (6.7 meters) electrical cable running from the outlet on the tractor. In addition, towed implement manufacturers were to make available either two taillights or two reflectors showing red to the rear and indicating as nearly as practicable the extreme left- and right-rear extremities of the towed implement. If implements mounted on the tractor obscured the tractor’s lighting, that lighting was to be moved or replicated on the implement. Mounted implements extending more than 4 feet (1.2 meters) to the left of the tractor’s centerline were required to have reflectors or an additional taillight. In addition, providers of self-propelled agricultural equipment were to make available lighting and marking consistent with that for tractors and tractor implement combinations.

A new standard for lighting and marking of agricultural tractors, self-propelled machines, implements, and implements in combination with tractors or self-propelled machines was published as ASAE Standard S279, “Lighting and Marking of Farm Equipment on Public Roads” in the 1965 edition of Agricultural Engineers Yearbook. It is instructive to consider the purposes for which this 1965 edition of the standard was aimed:

“1.1 To provide for lighting and marking of farm equipment for the purpose of promoting safety for the operator of the equipment and for the operators of other vehicles whenever such farm equipment is in operation, or is being transported, on a public road;
1.2 To provide manufacturers with a suitable guide for uniform practice in the industry; and
1.3 To assist regulatory bodies and educational groups in formulating uniform regulations and programs governing the operation or transport of farm equipment on public roads.”

The S279 standard (1965 edition) distinguished between lighting and marking for daytime versus nighttime transport on roadways, as well as between what was required for equipment with and without electric lighting systems. Daytime transport of farm equipment on roads required equipment with electric lighting systems to have a safety lamp showing red to the rear and amber to the front mounted at the left rear of tractors, self-propelled machines, and mounted or towed implements. Equipment without an electric lighting system was to display a warning flag or other generally accepted emblem during daytime transport.

Numerous revisions and enhancements have occurred to S279 over the ensuing 40 years. Most revisions and enhancements occur in one year and are published the following year. The current version, S279.13 “Lighting and Marking of Agricultural Equipment on Highways” incorporates provisions for at least two red, rear-facing stop lamps on machines designed for travel at speeds over 25 mph (40 km/h) and optionally for slower transport design speeds. These stop lamps are illuminated by braking control activation and deceleration rate of the equipment. Stop lamps may be combined with tail lamps or may be in addition to them, in which case they are placed at the left and right rear extremities and, if used to meet additional turn indicator provisions, must perform accordingly. However, if the machine is less than 4 feet (1.2 meters) wide, only one stop lamp is required. Any semi-mounted or towed implement designed for speeds over 25 mph (40 km/h), or any fully mounted implement that obscures the stop lamps on the propelling machine, must be fitted with stop lamps to take the place of those obscured. This is in addition to being fitted with lighting to take the place of any lamp on the propelling machine that is obscured. A detailed study of the history of the lighting and marking standard for agricultural equipment has been prepared by Murray Madsen (2008) from the University of Iowa.

ASAE Standard S318 “Safety for Agricultural Field Equipment” contains one section that specifically addresses tractor and machinery operation on highways. This section is shown below:

13 Travel on highways

13.1 Lighting and marking for agricultural field equipment shall conform to ANSI/ASAE S279 whenever such equipment is intended to operate or travel on public roads or highways.
13.1.1 The operator’s manual for the unit shall instruct the operator to turn on flashing warning lights whenever traveling on a highway, except where such use is prohibited by law.
13.2 Agricultural tractors and self-propelled machines with operator enclosures (cabs) shall have at least one rear-view mirror to permit the operator to see the highway behind the machine.
13.3 Hitch pins and other hitching devices shall be provided with a retainer to prevent unintentional unhitching.
13.4 Components that are retracted to decrease the width for highway transport shall have means to positively secure those components during highway transport. One or more types of locking systems may be used. Examples of locking systems are hydraulic cylinder locks and folding over-center.
13.5 Provisions shall be made for the use of auxiliary attaching systems per ANSI/ASAE S338 on towing machines and on equipment where expected uses include towing on highways by single point attachment.
13.6 For towed or semi-mounted implements, instructions in the operator’s manual and sign(s) on the machine shall specify a maximum transport speed.

3.2.7 LICENSED DRIVERS

The specific concern with this issue is youthful drivers of farm equipment on public roads, although it is possible for other unlicensed drivers to operate agricultural equipment on the same roads as motor vehicle traffic. One example of this is with Anabaptist populations who work for hire on non-Anabaptist agricultural operations and have access to tractors. Nevertheless, the greatest concern is with youth under the age of 16 who may not legally operate a motor vehicle on a public road but who may legally operate agricultural equipment on the same road. Only one study was found that addresses the issue in any detail. Doty and Marlenga (2006) published a study that reviewed state laws regulating youth who operate farm tractors on highways in the United States.

The impetus for this study was the 1994-enacted legislation in Wisconsin (becoming effective in 1997) requiring youth who operate tractors on highways to complete a tractor and machinery certification course. Doty and Marlenga (2006) systematically searched state vehicle codes for references to driver’s licensing and other requirements for youth and adults operating farm tractors on highways. As with most studies of this nature, other researchers that try to replicate such a study may come up with different results and conclusions because of imprecise terminology within statutes, and interpretations of those statues by state officials. The Doty and Marlenga (2006) findings included:

  • 14 states have some type of restriction for youth operating farm tractors on highways.
  • Six of these states require a driver’s license in order to operate farm tractors on highways regardless of driver’s age.
  • The remaining eight states have legislation that includes specific provisions regarding youth driving farm tractors or other agricultural equipment on highways. The exact provisions vary by state but include age, location, or time of day restrictions, as well as educational components.
  • Four of these states require youth tractor operators to obtain a special agricultural permit, license or certification.

Since 1968, the U.S. Department of Labor (USDOL, 1968) has declared many agricultural tasks to be hazardous for youth under the age of 16. This regulation is commonly referred to as Agricultural Hazardous Occupations Orders (AgHO). With certain exemptions, employment of youth under 16 for these hazardous tasks is illegal. The law does not apply to youth under 16 who are employed, either with or without compensation, by their parents or legal guardians. As part of this declaration, a procedure was established by the Department of Labor so that youths 14 and 15 years of age could be exempted from certain portions of the law. This exemption includes agricultural tractors and specific types of farm machinery. More specifically, the exemption states that with successful completion of a 10- hour training program, 14 and 15 year-old youths can be employed to operate a tractor of over 20 PTO horsepower (15 kW), or connect or disconnect an implement or any of its parts to or from such a tractor. This exemption assumes that youth are already familiar with normal working hazards in agriculture; if they are not a 4-hr orientation program to normal working hazards is required. Additionally, with successfully completing a 20-hour training program offered by 4-H and FFA, youths can be employed to operate specified farm machinery.

More important to this discussion is how the term “agriculture” is defined in this regulation. In the definitions section of this law, the term "agriculture" is defined to include: "farming in all its branches and among other things includes. . . preparation for market, delivery to market, delivery to storage or to market or to carriers for transportation to market." This statement allows a properly trained youth to haul produce and other products to markets, between farms, etc. As a rule, state motor vehicle regulations that are more restrictive than federal regulations take precedence over the federal regulations. For example, in the 14 states identified by Doty and Marlenga (2006) with laws regulating youth farm tractor operators on highways, youth may be prohibited from operating farm tractors on highways even if they have been properly trained under the AgHOs. In the other states without any youth licensing restrictions, the AgHOs supports 14 and 15 year old youths operating tractors on public roads and, with higher speed tractors, would allow them to operate tractors at speeds upward of 35-40 mph (56- 64 km/h).

2 Historically, ASAE standards were first published the year following formal adoption.


This document is from the
North Central Education/Extension Research Activity Committee 197 Cooperative State Research, Education, and Extension Service United States Department of Agriculture

Recommended citation: Committee on Agricultural Safety and Health Research and Extension. 2009. Agricultural Equipment on Public Roads. USDA-CSREES, Washington, DC.

Disclaimer and Reproduction Information: Information in NASD does not represent NIOSH policy. Information included in NASD appears by permission of the author and/or copyright holder. More

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