Preventing Death and Injury in Tractor Overturns with Roll-Over Protective Structures

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roll over protection on a tractorTractor overturns are the leading cause of occupational agricultural deaths in the United States. Between 1992 and 2005, 1,412 workers on farms died from tractor overturns. The Roll-Over Protective Structure (ROPS) was developed to protect tractor operators from death and disability from these events by providing a protective zone for the operator in during a tractor overturn. ROPS are most effective when used in conjunction with a seatbelt, which keeps the tractor operator inside the protective zone during an overturn. The effectiveness of ROPS has been well documented (Thelin, 1998). The National Institute for Occupational Safety and Health (NIOSH) has estimated that fatality rates due to tractor overturns could be reduced by a minimum of 71% if all tractors in the U.S. were equipped with ROPS.

In a recent issue of the Journal of Safety Research (vol. 39, issue 5, 2008), a NIOSH-authored article, “Tracking the Prevalence of Rollover Protective Structures on U.S. Farm Tractors: 1993, 2001, and 2004,” summarized the changes in the prevalence of ROPS use over an eleven year period. The data, which were collected for NIOSH by the U.S. Department of Agriculture (USDA), National Agricultural Statistics Service (NASS), show ROPS use has increased from 38% in 1993 to 51% in 2004 (an average increase of 1.2% per year). More recent NIOSH/NASS ROPS surveillance data indicate the prevalence of ROPS-equipped tractors reached 59% in 2006 (NASS, 2008). While the increase in ROPS-equipped tractors is encouraging, the slow rate of ROPS adoption continues to frustrate the agricultural safety community.

The Journal of Safety Research article shows that farms in the South and the West had the highest percentage of ROPS-equipped tractors at 52%, compared with 46% in the Midwest and 40% in the Northeast. Additionally, the older the age of the primary farm operator, the less likely tractors on the farm were equipped with ROPS. On farms with operators younger than 55 years, over 50% of tractors were equipped with ROPS. When the operator was 25- to 34-years old 57% of the tractors had ROPS. The lowest percentage of ROPS-equipped tractors was found on farms operated by farmers over 65 years of age at only 42%. Farms with a value of sales over $99,999 had the highest percentage of ROPS-equipped tractors (67%). The lowest percentage was on farms with a value of sales less than $10,000 (40%).

It may seem obvious that farmers with limited resources do not have the capital to buy new tractors or retrofit their existing tractors, and cost has been identified by farmers as one barrier to retrofitting ROPS on older tractors, even if they will continue to be used for decades. However, economics are not the only factors influencing reluctance to place ROPS on older tractors. Studies have shown that even with an economic incentive, ROPS acceptance by the farm operator was not 100%. In New York, only 12% of farm operators interviewed were willing to pay the $400 for a ROPS retrofit, while 40% said they would never accept a retrofit even if it were free (Kelsey, May, and Jenkins, 1996). A second study found that farm operators in New York were more willing to retrofit as subsidy offers increased, with a cost-sharing incentive of 75% to 90% encouraging the greatest number of farm operators to retrofit. However, even when offered a 100% subsidy, 20% of the interviewed farmers stated they would not retrofit an older tractor with a ROPS (Hallman, 2005). Common reasons given by farm operators for not placing a ROPS on older tractors include:

  • the ROPS are too tall to allow tractors to enter farm buildings or interfere with farm operations where low clearances are an issue (e.g., tractors used in orchards);
  • the belief, particularly among older farmers, that they know how to control a tractor, making ROPS unnecessary;
  • what they perceive as the inconvenience and time needed to purchase a ROPS and have it installed on their tractor.

These and the economic factors make campaigns to encourage equipping older tractors with ROPS difficult.

Although federal regulations and voluntary standards have been set as a means of reducing injury and death from tractor overturns, these measures have limitations. In 1976, the Occupational Safety and Health Administration (OSHA) required all agricultural employers to equip all employee-operated tractors manufactured after October 25, 1976, with ROPS and safety belts. This standard, which is still in effect today, does not apply to family members (family-only farms) and, since its inception, has not been enforced on farms with fewer than 11 full-time employees in 47 of the 50 states. California, Oregon, and Washington are the exception, and cover all farms with hired workers. These restrictions mean that only about 8% of all farms in the U.S. are covered by this standard. Another major effort to increase the use of ROPS was taken by the American Society of Agricultural Engineers (ASAE now the American Society of Agricultural and Biological Engineers, or ASABE). In 1985, ASAE adopted a voluntary standard, S318.10, which encouraged tractor manufacturers to install ROPS and seatbelts on all new agricultural tractors for use in the U.S. market. All major tractor manufacturers agreed to adopt this standard, and since 1986, nearly all new agricultural tractors sold in the U.S. have been equipped with ROPS and seatbelts as standard equipment.

It was anticipated that the voluntary ROPS standard would lead to a decrease in the number and rate of tractor overturn deaths on U.S. farms. Yet between 1992 and 2005, tractor overturn fatality rates have not decreased significantly because of the large number of older tractors in use on U.S. farms that are not equipped with ROPS. Based on the current rate of ROPS adoption, we would not expect to see fatality rates from tractor overturns in the U.S. to be at or near zero until sometime after the year 2020. The loss of life in the interim is unacceptable. The data suggest that incentive programs addressing the concerns of older farm operators and low-income farm operations may help increase retrofitting of ROPS on older tractors.

NIOSH, through its network of Agricultural Safety and Health Research Centers and the National Occupational Research Agenda (NORA) Agriculture, Forestry, and Fishing Sector Council, is making the retrofitting of ROPS on older tractors a major research and outreach priority. As a part of this process, we would like to hear your success stories or ideas about how to encourage the retrofitting of ROPS on older farm tractors and protect Americas farmers and farm workers.

—John Myers, MSF

Mr. Myers is a Health Statistician in the NIOSH Division of Safety Research.

Posted 1/5/09 at 10:03 am


  1. Hallman E. [2005]. ROPS retrofitting: measuring effectiveness of incentives and uncovering inherent barriers to success. J Agric Saf and Health 11(1):75-84.
  2. National Agricultural Statistics Service. [2008]. 2006 farm and ranch safety survey. Report No. Sp Cr 3-1 (1-08). Washington, DC: U.S. Department of Agriculture, National Agricultural Statistics Service.
  3. Kelsey, T. W., J. J. May, and P.L. Jenkins. [1996]. Farmtractors, and the use of seat belts and rollover-protective structures. Am J Ind Med 30:447-451.
  4. Thelin A. [1998]. Rollover fatalities–Nordic perspectives. J Agric Saf and Health 4(3):157-160.
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33 comments on “Preventing Death and Injury in Tractor Overturns with Roll-Over Protective Structures”

Comments listed below are posted by individuals not associated with CDC, unless otherwise stated. These comments do not represent the official views of CDC, and CDC does not guarantee that any information posted by individuals on this site is correct, and disclaims any liability for any loss or damage resulting from reliance on any such information. Read more about our comment policy ».

    Thank you for this update. My father in law who knew tractors like the back of hand was killed in a tractor rollover in 2000. I wish I had known about this then and perhaps the outcome would have been different.

    Reading your reasons for resistance though, I am sure he would score on all accounts. I hope this message may somehow get to the Grandpas out there who if they don’t want to do this for themselves, think of the sad little faces that were robbed of years more of hanging around with Gramps, let alone the unabated grief of widow and sons.

    The best way to identify a ROPS retrofit for your tractor is to contact a local equipment dealer selling the brand of tractor you need a retrofit for. If the tractor is not made anymore, but the brand was taken over by another manufacturer (e.g., New Holland covers Ford, CASE, CASE-IH, and some IH brands; AGCO covers White, Allis Chalmers, Massey Ferguson, and some other older brands), you could contact them to see what ROPS they have available. For the more common tractors made in the 1960s–1980s, a ROPS should be available. If the tractor is older than this, and is not a common make of tractor, locating a ROPS will be more difficult, although there are some companies who make ROPS for certain older tractors. You can locate a possible manufacture at the following website:
    If you live in the state of New York or in the state of Virginia, additional help is available for both locating a ROPS and with the reducing the cost of purchasing the ROPS. Information on these two programs can be found at the following websites:

    ◦New York:
    Unfortunately, most other states do not have an incentive program available to help offset the cost of retrofitting a tractor with a ROPS.

    Maybe a singular, clear message that speaks to their views “make your own decision to be safe—put on a ROPS”

    In 45 min program to about 40 farmers, I shared my own angst that “I do not know how I could live with myself if my teen aged daughter were killed in a rollover I knew how to prevent.” Then I left a dramatic pause for them to consider how this applied in their work. Marie had just started driving the tractor for haymaking. Two farmers took action to notify me about how they changed their risk after this decision point. One called the dealer that afternoon to install a ROPS to protect his 17 year old son. The second one decided to sell the tractor for antique tractor displays so his teenaged daughter would be safe. If two felt compelled to contact me, I bet there were others who also took action.

    Has there been research into other passive or active controls to PREVENT rollover, and are those technologies being put to use as old equipment is replaced? Are there any technologies that are safer when a tractor rolls into a bog or pond?

    Currently, the most effective passive engineering control to prevent tractor overturn deaths remains the ROPS and ROPS cab, which is why ROPS are standard equipment on nearly all new tractors sold in the United States. Tractor manufactures have changed the designs of tractors over time providing them with a wider wheel-base and a lower center of gravity, which makes the tractor less prone to overturn, but not overturn-proof.

    There has been research done in the past looking at sensors or other instruments that indicate when a tractor is about to overturn. However, these types of sensors have been used more for educational purposes rather than as standard equipment on new tractors. Two major reasons these types of instruments are not placed on tractors are: the sensor only tells the operator that tractor is about to overturn, but cannot tell the operator what corrective action to prevent the overturn; and, in general, there is not sufficient time for the operator to react and prevent the overturn when the sensor indicates an overturn is occurring (most fatal tractor overturns occur in less than 1 second).

    There has been a large body of research done on the environmental and physical characteristics that increase the risk of a tractor overturn. These include operating tractors on excessive slopes, improper hitching of towed equipment, hitching tow chains or tow straps too high on the rear of the tractor, and excessive speed when turning a tractor. Information on how tractor operators can reduce their risk of overturning a tractor are available from their local USDA state extension office, or by searching the following agricultural safety database:
    As for the hazards caused by ponds, bogs, canals, or other bodies of water, the most effect means is to not use tractors near these areas. If this is unavoidable, the next best option is to have the tractor equipped with a ROPS cab, which should provide the operator additional time to react to having the tractor overturn in to water. I am not aware of any other technologies that are commercially available that deal with this issue.

    I wonder if there was any study made of the center of gravity of all type of tractor in respect to the slope angle of the ground, on which the tractors are operated?

    Other option may be to install the simple clinometers on the tractors and indicate the critical angle, which should not go beyond, to assist the operators.

    There has been research done in the past looking at the issue of center of gravity and how that impacts the stability of farm tractors not only when on a slope, but also when lifting heavy loads with a front-end loader, or towing an object with a chain or tow rope. This research led tractor manufacturers to change the designs of tractors providing them with a wider wheel-base and a lower center of gravity, which makes newer tractors less prone to overturn, but not overturn-proof. Tractor manufacturers do provide general guidance on operating their tractors on slopes in the owner’s manuals that come with the tractor.

    There has been research done in the past looking at sensors or other instruments, such as clinometers, that indicate when a tractor is about to overturn. However, these types of sensors have been used more for educational purposes rather than as standard equipment on new tractors. One reason these types of instruments are not placed on tractors is that the sensor, or clinometer, only tells the operator that the tractor is about to overturn, but cannot tell the operator what corrective action to take to prevent the overturn. A second reason is that, in general, there is not sufficient time for the operator to react and prevent the overturn when the sensor indicates an overturn is occurring (most fatal tractor overturns occur in less than 1 second). Finally, clinometers may give the operator a false sense of security when operating a tractor on a steep slope since it cannot account for sudden changes in terrain, or obstacles on the slope (e.g., holes, rocks, logs) that can suddenly cause the tractor to overturn. That is why a ROPS is considered the most effective means of protecting an operator in the event of an overturn.

    I have wondered for a long time why we can pay farmers for conserving the land and water, and we do not offer direct subsidies to save the lives of farmers. I think funds could be made available through the USDA in a similar manner to conservation payments as a cost share for the practicem, if there was a political will to do it.

    The blog by John Myers describes very well the development in the use of ROPS. As John mentiones, the development in the percentage of tractors with ROPS is encouraging, while the development in the tractor overturn fatalities is not as encouraging. The main reason is that the old non-ROPS tractors are not disappearing, and not retrofitted, and they are still involved in a lot of fatal overturns. I wanted to add another note: there might be a new problem with the open operator station FOLDABLE two-post ROPS that are now very comon on compact utility tractors and zero turn mowers. We have investigated two fatalities in Iowa where such tractors had the FOLDABLE ROSPS in DOWN POSITION. FACE reports of these cases are on the NIOSH FACE website. Since these cases, I have started to observe these tractors and mowers, not in a systematic way but wherever I see one.

    It appears that a high percentage of the foldable ROPS are usually kept in the down position – which makes the ROPS ineffective if needed, and perhaps even more harmful than not having one. So – I have thought some type of warning system, similar to car seatbelt warning systems, could perhaps remind the operators that ROPS in the down position is a hazard.

    Also, public awareness campaigns and education about this issues should perhaps be emphasized.

    I am a farm safety professional AND a small farm operator. One of my own tractors does not have a ROPS; it is 50 years old, still works fine, and to the best of my knowledge nothing is available in the way of retrofit parts. I am cautious about how I use this tractor but recognize there is some risk. It’s hard to think about just scrapping out this useful tractor. I know I can’t afford to buy a newer one to replace it. So my choices are to try a non-approved shop built ROPS or just continue to be cautious. The use of non-ROPS tractors is a very tough problem to solve.

    I just wanted to make a clarification to one portion of the article:

    “In 1976, the Occupational Safety and Health Administration (OSHA) required all agricultural employers to equip all employee-operated tractors manufactured after October 25, 1976, with ROPS and safety belts. This standard, which is still in effect today, does not apply to family members (family-only farms) and, since its inception, has not been enforced on farms with less than 11 full-time employees. These restrictions mean that only about 8% of all farms in the U.S. are covered by this standard.”

    The 8% figure is slightly misleading. This may be true for areas covered by Federal OSHA standards. However, many state-plan states have their own rules which do not have the enforcement limitations of Federal OSHA, and as such do inspect farms with fewer than 11 full-time employees.

    Thank you for your comment. You raise an interesting point about State-plan and Federal-plan programs, which we will include in our post. However, the impact is not as great as one might think. Based on what I have been able to determine, only three of the 21 state plans enforce their occupational safety and health standards on farms with fewer than 11 employees: California, Oregon, and Washington. While the remaining 18 state plans could choose to include farms with fewer than 11 employees, they would need to do so by using dedicated state funds, and no Federal funds. As I understand it, California, Oregon, and Washington support their agriculture OSHA programs with “state-only” funds. The other 18 states have chosen not to do this.

    A second issue is that OSHA standards only apply to farms that have hired employees, even for state plans. Based on the 2002 Census of Agriculture, there were about 61,000 farms in CA, OR, and WA that reported using hired or contract farm laborer, which represents 39% of the farms in these three states (45% for California, 28% for Oregon, and 38% for Washington). This represents a significant coverage of farms in these three states. Still, these 61,000 farms represent just 3% of all farms in the United States. So, while it is important that these three states continue their programs, from a national perspective, the impact is limited.

    The best way to prevent tractor roll-overs is just to watch instructional videos prior to operating a tractor. Another way you could help is maybe if a balance indicator could be installed in a tractor, and when it was dangerously unbalanced then an alarm would sound.

    Thank you for your comment. Please see the reply to comment 5 regarding balance sensors/instruments.

    Recently I have done two accident investigations regarding tractor accidents. In both instances, the tractors had ROPS, however employees were not wearing seatbelts. The employer had provided training in both instances.

    During the course of my interviews with other employees and the victims, I asked if there was anything the employees should do differently if the tractor has ROPS. They all knew they were to wear seatbelts. When I pointed out that the victims were not wearing seatbelts, 8 of 10 on one inspection and 5 of 5 on the second inspection stated the tractor did not have ROPS. I took them out to the tractor in question, or showed them photographs to verify it was the same tractor. They all agreed it was the tractor involved in the accident. I again asked about ROPS. The answer was the same – this tractor did not have ROPS. When employees were asked what ROPS was, they said it was a structure that would prevent the tractor from rolling and crushing them. When I pointed out the ROPS and asked what that was, they did not know. I asked them to describe what ROPS looked like. All thought it was an enclosed cab or canopy. I thought this was interesting. One of the employers had their insurance company provide the training, the other had a private consultant. Both thought the employees understood based on their responses to the questions. In short, it is important to walk out to your particular tractors, all types, and point out safety features. As a side note, which may or may not have relevance, all of those involved in accident or interviewed were non-English speaking, with exception to the two who correctly identified the ROPS.

    I guess this is a good reminder about safety training (and “expert” consultants as trainers.) It’s dangerous to assume that our words (jargon?) are understood as we mean them. This audience apparently took “structures” to mean something a lot more elaborate than a simple roll-bar; they thought they understood, but actually didn’t (the most dangerous kind of miscommunication.) It seems that “expert” trainers (consultants, insurance companies, etc.) may not be competent in this regard.

    I am a student at the University of Miami in an environmental and occupational health course. In reviewing some of the studies done on ROPS, I noticed that they seem to focus exclusively on either monetary compensation or education. Has NIOSH looked into programs that combine risk education with incentives to help farmers retrofit their tractors?

    Hallman’s (2005) study of the barriers to retrofitting show that the high cost, height of ROPS structure, and opportunity cost of sending tractors away for retrofitting are the biggest barriers to implementation. An education campaign about foldable ROPS could address complaints about the structures’ height. But what can be done about the cost for farmers to send their tractors away to be retrofitted? Would it be feasible for states to provide some type of “traveling repairman” to assist farmers with the retrofitting, thus eliminating the need to send the machines away for days or weeks?

    Thank you for your question. As you point out in your entry, a successful ROPS retrofitting program requires more than just informing the farmer that overturns are dangerous. Traditional ROPS educational programs tended to focus too heavily on this approach. Newer ROPS promotion programs tie together the concepts of social marketing, risk communications, and incentives to create a more effective approach. The most complete program developed to date is in the state of New York. The program does have traditional risk communications as part of the program, but the messages were vetted through New York farmers to see what messages worked and which messages did not. The next part added in an monetary incentive to help offset the cost of placing a ROPS on a tractor, but the program does more than that. The program includes a resource center that will locate the different types of ROPS that are available for a tractor (i.e., cabs, two-post ROPS, folding ROPS), who the manufacturers are, what the different costs will be, where to have the ROPS installed, what it would cost to have the ROPS installed at their farm, or whether the ROPS could be installed by the farmer themselves. Each piece of the program is designed to remove as many of the barriers as possible identified by Hallman (2005). More details about the New York program can be found at the following website:

    Ultimately, as you allude to in your comments, successful programs have to meet the needs of the farmer to be successful. The New York program is based on this approach, and does show that a well thought out ROPS promotion program can work. The next step is to take the lessons learned from New York and adapt them to other parts of the US that have large number of tractors without ROPS.

    Good information. I have a situation where a tractor is being used in an area where ROPS cannot be used (inside a greenhouse). Saw employees operating the tractor and not wearing a seatbelt. I inquired as to why and response was the exemption under 1928 standard. My response was since there is no exposure to rollover, then a seatbelt policy must be enforced as if the operator were to hit a solid stationary object he would likely be thrown from the tractor. Looking for comments in support and against this premise.

    While it may seem proper to recommend that a person wear a seatbelt when operating a tractor without a ROPS in an area with a low risk of an overturn, the OSHA Standard 1928 Subpart C, 1928.51 exempts the use of ROPS and seatbelts on low profile tractors used: in orchards, vineyards, or hop yards where the vertical clearance requirements would substantially interfere with normal operations, and while their use is incidental to the work performed therein; inside a farm building or greenhouse in which the vertical clearance is insufficient to allow a ROPS equipped tractor to operate, and while their use is incidental to the work performed therein; or with mounted equipment which is incompatible with ROPS (e.g., cornpickers, cotton strippers, vegetable pickers, and fruit harvesters). In addition, 1928 Subpart C, Appendix A states: “Securely fasten your seat belt if the tractor has a ROPS.” A reason not to wear a seatbelt on tractors without ROPS is because the operator would be trapped on the tractor by the seatbelt if it did overturn.

    If the tractor is ever used outside of the greenhouse, you may want to find out if the tractor can be fitted with a folding ROPS. These ROPS are just as protective as a regular ROPS when they are in the up position, but fold out of the way when the tractor is used in a low clearance area such as a greenhouse. You may consider contacting the manufacture of the tractor in question to see if a folding ROPS design is available for that tractor model.

    Our government should offer some sort of incentive programs to farmers who farm safely and efficiently with Green initiatives tied into the campaign somehow.

    Ten Commandments of Tractor Safety

    Know your tractor, its implements and how they work. Keep your tractor in good condition.

    2. Use ROPS and seat belt whenever and wherever applicable. We recommend the use of ROPS (Rollover protective structure) in almost all applications. Most tractor fatalities are caused by overturns. If the tractor is equipped with ROPS, always wear the seat belt.

    3. Be familiar with your terrain and drive safely. Use caution on slopes, slow down for all turns and stay off the highway whenever possible. Elementary, but all too often neglected.

    4. Never start an engine in a closed shed or garage. Carbon monoxide is colorless, odorless and deadly.

    5. Always keep your PTO properly shielded. It rotates with the strength of 500 men.

    6. Keep your hitches low and always on the drawbar. Otherwise your tractor might flip over backwards.

    7. Never jump off a moving tractor or leave it with its engine running. A runaway tractor can be extremely dangerous.

    8. Never refuel while the engine is running or hot. And do not add water to radiator while the engine is hot; hot water can erupt and scald.

    9. Keep all children off of and away from your tractor and its implements at all times. A tractor’s work is not child’s play.

    10. Never be in a hurry about anything to do with your tractor. Take your time and do it right.

    Here is the newest guide to retrofit ROPS, “The Kentucky ROPS Guide”, developed with NIOSH funding and designed to be a user-friendly, online database of available ROPS searchable by make and model of tractor:

    It replaces the guides published by Marshfield Clinic.

    Hi… Nice Blog. You Have given the Valuable Information on it. The information about tractor partsis very useful for me. I am making a project on Tractor parts.

    I would like to see a rule simular to American Disabilities Act (ADA) and Life Safty Code (LSC) we use for buildings. If a building is older it may not have to meet the most recent codes as long as it was in code when built and is otherwise safe. However if the building is remodeled or sold is has to be brought up to current codes. In this situation as tractors are sold or the farm changes owners (even in family operations) the tractor would be required by law to have a ROPS installed. This still would not get every older tractor but would eventually get more than we currently see.

    Perhaps of interest… a Blog site for farmers and ranchers to voice their opinions about ag safety and health!

    The Next Generation: Farm Safety and Health Blog at [] is hosted by the Great Plains Center for Agricultural Health, University of Missouri, and Farm Safety 4 Just Kids. This Blog offers a place for farmers and ranchers to share their opinions about farm safety and health. Together, our organizations offer information, tips, and stories to get the Blog conversation started. Beyond that, we want to hear what farmers and ranchers think.

    Nebraska is an important agricultural state. As a former University of Nebraska Extension Educator, my programming included Tractor Safety training and education allowing youth basic education with a tractor driving skills demonstration and passing a tractor test.

    My research on AGRICULTURE SAFETY EDUCATION AND AWARENESS has shown tremendous resources from various sites addressing Farm Safety. FFA chapters in Nebraska each fall have Farm Safety week showing youth risks on farms and ranches. Several agricultural organizations, interested individuals and state agencies with my involvement are addressing AGRICULTURE SAFETY AWARENESS to media .

    As the Extension Educator, I taught safe handling of livestock to youth, safe use, handling and storage of pesticides, safety when riding school buses with a evacuation drill, working with FFA Ag Educators and school administrators and agricultural organizations. Nebraska’s youth are the future adults shaping communities.

    Tractor turnover, overturn or roll-over is the major cause of tractor-related deaths. Most overturn deaths are prevented with seat belts and roll-over protective structures (ROPS). fatalities, 93 were injuries and four were noninjuries.

    This issues are always taken for granted. I believe the manufacturers also need to design a type of tractors which is safe or I mean can lessen the damage if accidents occur.

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