Agricultural Equipment on Public Roads

  • Committee on Agricultural Safety and Health Research and Ext,


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



  • There is little attention paid to issues surrounding safe movement of agricultural equipment on public roads by federal, state or local governments.
  • Public roadway crashes involving agricultural equipment are, comparatively, few in number but an important part of overall crashes involving agricultural populations.
  • The impacts of changing demographics that characterize the urban/rural interface are not well researched or understood.
  • Many details of public road crashes involving agricultural machinery and motor vehicles are unknown or lack sufficient detail to aid prevention efforts.
  • There is no available data that provide for an accurate assessment of the injuries, deaths, or property losses associated with motor vehicle crashes involving horsedrawn buggies or implements.


The continuing urbanization of traditional agricultural production areas has led to a substantial increase in the mix of agricultural equipment and licensed motor vehicles on public roads (Committee on Agricultural Safety and Health Research and Extension, 2003). Farms are increasing in size, often by the acquisition of non-contiguous land. There is a trend towards greater management of farms by renters and leasers with custom operators performing many field operations. Many farm commodity prices are at an alltime high, and new production techniques continue to result in higher levels of production per unit. There is current interest in biomass as a fuel source. This suggests that farmers’ and ranchers’ production output will reach new levels. Add to these factors the incursion of housing developments, shopping plazas and other urban developments onto lands once used exclusively for agriculture, and regular movement of urban dwellers to small lifestyle acreages. A result of all these factors and changes is an increased mix of farm equipment with faster moving motor vehicles on public roadways and is referred to collectively as the rural/urban interface.

The percent of crashes where one or more died defined as rural or urban is 53.7% and 44.1%, respectfully, with the remaining 2.2% identified as unknown. The highest percent of fatal crashes in rural locations--42.5%-- occurred on rural roads posted at 55 mph (88.5 km/h) or higher (NHTSA 2007). While farm tractors and other self-propelled equipment (excluding farm trucks) number less than .05% of total motor vehicles nationally, the percentage of fatal motor vehicle incidents involving farm equipment is almost five times higher (Hanna et al, 1997).

According to Abrams (1993) the United States nighttime highway fatality rate is 3-4 times higher than that of daytime. While falling asleep at the wheel and driving while intoxicated are significant factors, reduced vision plays a substantial role. This is pertinent because of the aging population of farmers and persons in rural areas in general. As we age, there is a tendency to become farsighted and not to see as clearly up close. In addition, the range and speed at which the pupil adjusts to differing levels of illumination decreases. More specifically, there is a 50% reduction in retinal illumination at age 50

compared to age 20 and 66% reduction at age 60 (Abrams, 1990). At night, the peripheral retina must be stimulated at sufficient intensity for an object to be detected. If the stimulus is not strong enough, the brain is unable to process the information in time to avoid a collision. Essentially, the elderly need more light.


Studies reporting crash data involving farm equipment or farm vehicles are difficult to compare because terminology is not precise. For example, a state’s definition of farm vehicle may or may not include pickup or livestock trucks, depending in part, upon whether or not a state has an exemption for trucks that are operated only within a certain distance of the farm operation. Additionally, many studies do not precisely define terms such as farm vehicle or farm equipment. For these reasons, comparisons of crash data among states must be interpreted very cautiously. In the studies reported below, the terms vehicle and non-farm vehicle typically include all types of motor vehicles, including pickup and dump trucks. The terms farm vehicle and agricultural equipment typically includes tractors and self-propelled agricultural machines, and may or may not include towed farm equipment.

Peek-Asa et al. (2007) recently reviewed characteristics of crashes between farm equipment and motor vehicles in Iowa. Included in their article were findings and points from previous studies relating to crashes between agricultural equipment and motor vehicles.

  • Crash fatality rates in the most rural counties are almost double the rate in urban counties (Eberhardt et al., 2001; Baker et al., 1992).
  • Rural crashes are more frequent, more severe, and more likely to result in death than urban crashes (Baker et al., 1987).
  • Certain types of crashes, such as those between motor vehicles and farm vehicles, are unique to rural environments and usually involve slow moving tractors with trailing equipment and higher speed motor vehicles (Peek-Asa et al., 2004; Costello et al., 2003).
  • The environment of the rural road contributes to increased crashes and more severe injury outcomes (Graham, 1993; Karlaftis & Golias, 2002; Peek-Asa et al., 2004).
  • In crashes involving farm vehicles, the farm vehicle occupant was killed nearly twice as often as occupants of the other vehicle (Gerberich et al., 1996).

Contrary to the findings of Gerberich et al. (1996), Peek-Asa et al. (2007) found that non-farm vehicle drivers were 5.2 times more likely to be injured than farm vehicle/equipment drivers. Peek-Asa et al. (2007) attributed these differences in findings to differing crash criteria. For example, Gerberich et al. (1996) examined only fatal outcomes while Peek-Asa et al. (2007) examined all reported crashes regardless of injury outcomes.

Peek-Asa et al. (2007) also noted that their findings were similar to those found by Pinzke and Lundqvist (2004).

Costello et al. (2003) examined the public health impacts of farm vehicle public road crashes in North Carolina. As reported by Costello et al. (2003), this study included a comparison of farm vehicle public road crash rates among the states of Florida, Iowa,

Michigan and North Carolina. These data are reported in Table 1 below (Table 2 in original document) and illustrates a wide range of incident rates among these states.

Table 1. Comparison of farm vehicle public road crash rates for selected U.S. states.

Average Number of Cases per Year (resulting in injuries)
Population (1999 est.)
Average Number of Crashes per Day (365 days/year)
Average number of Crashes per 100,000 Population per year



15.1 million[b]





9.9 million[b]





2.9 million[b]



North Carolina


7.7 million[b]



[a] University of Florida, 1991
[b] U.S. Census Bureau, 1999
[c] Michigan Farm Bureau, 1999
[d] Schwab, 1997
[e] Hughes and Rodgman, 2000
Table reprinted with permission from ASABE

Costello et al. (2003) further indicated that 2 in every 100 crashes involving tractors, which may or may not be towing other farm equipment, and 1 in every 100 crashes involving other farm equipment (self-propelled or towed farm vehicles other than tractors) leads to a traffic death. The concern among farmers about the risk of driving agricultural equipment on public roads was revealed in North Carolina (Luginbuhl et al., 2003). This study focused on farmers’ perceptions of roadway safety. The study was instigated after a group of farmers in one region of North Carolina reported an increase of traffic on rural roads and their need to drive their equipment on these roads was viewed as their number one workplace hazard. In their review of farm equipment crashes, tractors were found to be involved in the majority of crashes on roadways. When these crashes occurred 34% of the drivers of non-farm vehicles were cited. Typical citations included failure to reduce speed, improper passing, and driving left of center. In 23% of the cases where the farm operator was issued a citation, lighting and yield violations were noted. In at least 11% of the cases where the farm operator was cited, the crash occurred in the evening and the tractor was not utilizing adequate lighting.

Additionally, when asked about their safety precautions, 92% of the study participants responded they used signal lights to warn others and 88% indicated they had an SMV emblem on the back of their equipment. Interestingly, though, when asked questions on whether other farmers knew the lighting requirements for farm equipment traveling on public roadways or whether most farmers were aware of the safety marking for farm equipment recommended by the American Society of Agricultural Engineers (ASAE) there was not strong agreement (Note: ASAE changed their name to American Society of Agricultural and Biological Engineers (ASABE) in 2005). A majority of respondents agreed that an effective way to reduce crashes would be to ensure that: a) all farm vehicles had blinking or flashing lights; b) road officials placed diamond-shaped caution signs showing a tractor ahead on roads with heavy farm traffic; and c) roadway shoulders were wide enough to allow farmers to drive totally on the shoulder. Finally, the study found that most farmers believed that driving their tractor on rural roads was more dangerous now than it was five years before. A similar concern was expressed in 1990 in a survey reported in a Farm Journal magazine story (Ottey and Fink, 1990). In this survey, farmers reported that their number one concern was that of public road travel to reach fields and markets.

A more recent study by Costello et al. (2008) examined driver, vehicle, public roadway, and farm enterprise characteristics for their combined association with farm vehicle public roadway crash group membership. North Carolina farmers experiencing a public roadway crash from 1992-2003 (n=200) were compared with a non-crash control group (n=185). The researchers found that five characteristics were associated with increased odds of crash group membership in the combined model. These characteristics were: 1) use of non-English speaking drivers; 2) use of non-family hired help drivers; 3) types of non-farm vehicle public road use; 4) farm injury history; and 5) use of younger farm vehicle drivers.

While acknowledging several limitations associated with their methods and instruments, the majority of their findings were in the expected direction, based on other studies cited in their literature review. Two findings that were not in the expected direction—increased odds of crash involvement—were that farms with older farm vehicle drivers and farms with low farm income were less likely crash group members. A recent study in Iowa (Freeman et al., 2008) found that a sample of 1,343 Iowa farmers did not rank transporting agricultural equipment on public roadways as a very stressful event in comparison to numerous other events. Potentially stressful events could be ranked between 100 (most stressful) and 0 (least stressful). Transporting agricultural equipment was ranked 53.2%. One message that these recent studies (Costello et al, 2008; Freeman et al., 2008) give is reinforcement that there is still much to be learned about the issues and characteristics of operating agricultural equipment on public roadways.


Several researchers have identified some of the common types of crashes involving agricultural equipment (Costello et al., 2003; Hughes and Rodgman, 2000; Schwab and Miller, 1995). These common types of crashes include rear-end, left-turn, passing, crossroads, and oncoming collisions. Costello et al. (2003) reported five categories of farm vehicle operator traffic citations as vehicle equipment, unsafe movement, failure to yield, being left of the center line, and not signaling. These account for approximately 70% of all North Carolina farm vehicle public road citations from 1995-1999. There are also individual reports of these types of collision events from all around the nation that help illustrate the nature of these events.

Rear-End Collision. The rear-end collision is a common type of farm equipment vs. motor vehicle collision on public roads. Lehtola et al. (1994) reported that of fatal incidents involving tractors and motor vehicles that occurred on Iowa public roads from 1988-1992, 43% (6 of 14) were the tractor being hit from the rear. Gerberich et al. (1996) reported that a large proportion of farm vehicles are struck in the rear during daylight (24%) as well as night, dawn, or dusk hours (65%), compared with non-farm vehicles (4% and 4%, respectively). Costello et al. (2003) reported that the top traffic citation issued among North Carolina non–farm vehicle operator violations was failure to reduce speed (29.5%). The speed difference between agricultural equipment and other motor vehicles creates this potential hazard. It is easy to misjudge speed when approaching a slow-moving vehicle, you have only a few seconds to react and slow down. Agricultural safety professionals frequently warn about this hazard (Abend and Hallman, 1995; Schwab and Miller, 2004; Petrea, 2004). For example, if you’re driving 55 mph (89 km/h) and come upon a tractor that’s moving 15 mph (24km/h) , it only takes five seconds to close a gap the length of a football field between you and the tractor. An actual example of this type of collision involved a tractor pulling two tobacco trailers on a highway a little before 6 PM being struck from behind by an automobile; the tractor operator was killed and the automobile operator was charged with failure to reduce speed.

Left-Turn Collision. The left-turn collision is another frequent type of farm vehicle collision on public roads. It happens when the farm equipment is about to make a left turn while the motorist behind the farm vehicle decides to pass. Schwab and Miller (1995) reported that there were 297 such collisions in Iowa during a five year period and that represents 22% of all farm vehicle collisions recorded. An actual example of this type of collision occurred when three people were injured when a tractor was turning left and was struck by an auto attempting to pass. The injured were the tractor operator, and the vehicle’s driver and passenger.

Passing Collision. Costello et al. (2003) reported that the second most common traffic citation issued among North Carolina non–farm vehicle operator violations was improper passing (17.0%). Many collisions also occur when motorists pass farm vehicles going in the same direction. Some farm operators haul equipment that is extra wide or long, which motorists don’t consider when they plan to pass. An actual example of this type of collision involved a car passing a tractor with a mower and the car struck the tractor wheel weights. Too few of the motoring public are aware of need not to pass at farm field entrances and farm building driveways.

Crossroads Collision. Farm operators transporting agricultural equipment face a challenge of taking their slow-moving equipment across an intersection. This becomes even more challenging when the cross traffic is moving at a high speed. An actual example of this type of collision involved a westbound combine failing to yield to a southbound semi at a highway intersection.

Oncoming Collision. Many collisions also occur when motorists pass oncoming farm vehicles. Some farm operators transport equipment that is extra wide or long, which motorists don’t consider as they approach the farm equipment. An actual example of this type of collision involved a man in a car being killed after striking a planter being towed behind a tractor. The car then crashed through a guardrail and into the roadside ditch.


A recent Successful Farming magazine story provides an example of how clear distinctions between rural and urban spaces are disappearing. Randy and Cheryl Miller had moved their farming operation 3.5 miles (5.6 kilometers) north of Ankeny, IA, when they were married 30 years ago. “Now Ankeny’s on our south fence line and across the road”, say the Millers (Tevis, 2008, p38). Increasingly, there is also a lack of space on rural roads. For example, in the same Successful Farming issue, Dr. Robert Aherin, University of Illinois extension agricultural safety specialist, noted that most paved rural roads are 18-20 feet (5-6 meters) wide while 70% of farmers in a Successful Farming online panel survey indicated they owned machinery over 13 feet (4 meters) wide (Tevis, 2008, pp36-37).

Wide machinery also becomes a big issue when farm machinery has to cross a rural bridge or work its way around utility poles, mailboxes and road signs. In many areas it is impossible for modern farm machinery to travel down rural roads and not take up well over ½ the road. The height of modern machinery and lower hanging pole lights, traffic signs, and utility lines and cables results in equipment shifting partially into the left lane to avoid these obstacles. Space is also an issue from the perspective of new divided highways in rural areas to handle increased traffic volumes because middle sections for crossing divided highways need to be wide and deep enough to safely handle today’s large machinery.

Any examination of safely moving agricultural equipment on public roads should look at the perspectives of both agricultural and non-agricultural populations. While no research was found that directly compared the perspectives of these two populations on the same set of issues, surveys and interviews with farmers clearly show that they think the hazards and risk associated with moving their machinery on public roads are primarily due to the actions of the non-agricultural motoring public (Luginbuhl et al., 2003; Tevis, 2008). The reports by Luginbuhl et al. (2003) and Tevis (2008) suggest that farmers believe that traditional rural dwellers (including farmers) are more understanding and knowledgeable about encountering slow moving farm equipment on the road than urban and suburban dwellers, and that traditional urban dwellers are less patient and understanding when farm equipment slows their travel speed. Furthermore, it is not clear how well urban or suburban drivers understand what the lighting and marking on farm equipment means when encountering it on public roads.


One transportation issue that is having a growing impact on some rural communities is the rapidly expanding presence of horse-drawn buggies and implements on public roadways being operated by members of Old Order Anabaptists communities, including the Amish and Old Order Mennonites. Members of these communities hold to selective and cautious use of technology to protect their families, communities and way of life. Some historians and sociologists argue that the use of horse-drawn vehicles is one of the most recognized or distinguishing features that separate Old Order Anabaptists from the rest of the culture (Hostetler, 1992; Scott, 1981; Kraybill and Olshan, 1994). Intentional rejection of personally owned motor vehicles and farm tractors, and reliance on horse powered transportation and farm implements are intended to keep Old Order families in closer proximity, keep farms smaller, present a witness of humility, and reduce the likelihood that their means of transportation would cause injury or death to other users of public roadways.

Historically, Old Order Anabaptists have been primarily concentrated in small rural communities in Pennsylvania, Ohio, and Indiana. Their small numbers and desire to remain separate from the world around them led to generally few highway-related problems. When collisions did occur between motor vehicles and horse-drawn vehicles, it was primarily the Old Order Anabaptists who received the brunt of the losses. Due to an explosive growth rate, however, there are currently approximately 375 Old Order Amish communities located in twenty-seven states and the province of Ontario, Canada. In addition, there are other expanding groups such as Old Order German Baptists and Wenger Mennonites who still rely on horse-drawn vehicles for transportation and farm work. In some counties such as Lancaster County, Pennsylvania; Holmes County, Ohio; and LaGrange County, Indiana, there are several thousand horse-drawn buggies and implements that are used on local roads and the number of buggies may exceed the number of licensed motor vehicles. The result has been a growing number of reported highway crashes involving horses and buggies, some of which have involved multiple fatalities to buggy occupants.

Even though Old Order Anabaptist populations may, on the surface, appear to have many similarities, there are no uniform standards among the many affiliations of Old Order Anabaptists with respect to the design and use of horse-drawn carriages and implements. For example, buggies can be black, white, gray or a combination. Some affiliations within these communities allow rubber tires while others don’t. Some allow the use of electric lights, reflective tape and Slow Moving Vehicle (SMV) emblems while other groups forbid their use (Kraybill and Olshan, 1994). These differences, and the tenacity to which they are defended, have been seen as barriers to developing uniform standards designed to enhance the safety of operating horse-drawn vehicles on public roadways.

The use of the SMV emblem on buggies has been central to one of the more intense conflicts that have occurred between Old Order Anabaptists groups and the general public. In some cases where the local pressure to adopt SMV emblems, reflective tape and electric lighting has intensified, the non-complying Old Order families simply moved to a more receptive community or to where the codes were not so severely enforced by local law enforcement. In Minnesota a group of Old Order families known as Swartzentrubers refused to use the SMV emblem and were ticketed by local law enforcement. This case was eventually reviewed by the U.S. Supreme Court and the decision of a lower court to overturn the citation was affirmed on the grounds of this group’s beliefs that compliance with the state marking and lighting codes prevented them from freely practicing their religion (Zook, 1993).

There are no directly available data that provides for an accurate assessment of the injuries, deaths, or property losses associated with motor vehicle crashes involving horsedrawn buggies or implements. Some studies, however, can be considered suggestive. For example, a study of 217 farm-related injuries to children under the age of 18 from 14 states and Canada documented during 2002 identified less than one percent involving motor vehicle-related crashes or highway-related incidents (Gilliam et al., 2007). Based solely upon the frequency of injuries reported within the Old Order Anabaptist community, it would be difficult to make a strong case that the highway-related incidents they experience should be a high priority for intervention activities compared to other injury events. It does appear, however, that these incidents are occurring more frequently and often result in multiple fatalities and severe injuries because of the limited protection provided by horse-drawn carriages. In other words, the probability of these events may be low, but the severity of the consequences is high.

Grassroots efforts within the Old Order communities, primarily facilitated by Cooperative Extension programs in Pennsylvania, Ohio, and Indiana have resulted in a substantial increase in the voluntary use of enhanced marking and lighting on Old Order Anabaptist buggies and farm implements. In LaGrange County, Indiana, for example, the use of SMV emblems increased from less than 30% to over 85% through a communitywide awareness campaign.

Some communities have enhanced the safety of operators of horse-drawn buggies and implements by providing wider shoulders or “buggy lanes” along the road for these vehicles to operate outside the stream of higher speed traffic. Other communities have recognized the potential hazards associated with the co-mingling of high and low speed vehicles and have responded by reducing the posted speed limits and placing warning signs where there is frequent use of horse-drawn buggies and implements.

A national Amish buggy safety committee, which is comprised of buggy manufacturers from across the United States, has addressed issues such as the use of L.E.D. (light emitting diode) lighting technology, high capacity/long life gel-type batteries, use of retro-reflective tape and strobe lights, and the need for training younger buggy operators. A growing number of Old Order buggy and harness shops now carry a wide variety of safety accessories to help make buggies and implements more visible to other highway users.

In 2008, the American Society of Agricultural and Biological Engineers (ASABE) completed a standard that established a unique identification system for animal drawn vehicles on public roadways and highways. The ANSI/ASAE EP576.1 standard, "Lighting and Marking of Animal Drawn Equipment," is intended to complement existing laws, rules and regulations in individual states, providences and municipalities to provide a consistent lighting configuration for horse-drawn vehicles. The recommended practice includes proper lighting and marking of both the vehicle and the animal, such as the use of headlamps, tail lamps, battery-operated or generator-powered lighting systems, and retro-reflective material, as well as the display of the slow-moving emblem. The Recommended Practice will affect consistency with all carriages, carts, and buggies, not just those in Amish communities. It appears that the Old Order Anabaptist community is becoming more accepting of the use of marking and lighting accessories that meet current voluntary consensus standards.


There are additional issues which anecdotally are known to increase hazards and risks for the motoring public but for which there appears to be little to no publicly available documentation. Some of these issues are:

  • Collisions with farm animals (e.g., a cow, sow or horse) that are on a road as a result of a broken fence or open gate and are hit by the motorist.
  • Rural road bridge damage and failure from larger and heavier grain and cotton trucks and wagons, manure spreaders, and tractors and tillage equipment.
  • Agricultural equipment carrying hazardous materials like anhydrous ammonia, pesticides and animal waste in quantities that can pose significant environmental and personal injury risks.
  • Use of alcohol and other drugs during operation of agricultural equipment on public roadways.

Likewise, there are ideas which could possibly increase the safety of farmers operating their equipment on public roads but for which there is little to no publicly available documentation regarding implementation or effectiveness. Some of these ideas are:

  • Use of escort vehicles. Other large size vehicles with wide loads are required to use one or more escort vehicles. This suggests that a motor vehicle with hazard lights flashing traveling in front of, behind, or both, of agricultural equipment provides increased visibility and warning to other motorists for immediate caution. Importantly, there is scarce evidence that either escort drivers or motorists know what they are responsible to do.
  • Use of fixed and mobile rural road signs that warn of tractors or other slow moving farm equipment, especially in heavy traffic times (spring tillage, fall harvest) or locations (roads leading to rural storage facilities or markets).
  • Farmers making greater use of trucks, including semi-trucks, to haul produce to storages or markets rather than using tractors and wagons. This is already occurring as farms become larger and more dispersed but as a specific intervention to reduce farm equipment vs. motor vehicle crashes, it has not been evaluated.

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.

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