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Bikecentennial had the unusual advantage of an accurate tabulation of the total number of miles traveled and the accidents that took place along the TransAmerica Trail. This is one of the first reports on bicycling accidents able to identify how and why such incidents take place, to establish a base rate, to list probable major and minor causes, and to indicate the severity of all injuries, including those that often go unreported.

Two techniques were used in tabulating this information. First, a zero deductible medical insurance policy was carried on each rider, encouraging treatment for even the most minor injuries. The report from the insurance company helped in the tabulation of all medically treated injuries A second source of accident information was an accident questionnaire sent to domestic riders by Bikecentennial.

The data in the tabulated questionnaires includes 399 accidents (308 individuals). In our questionnaire we defined an accident as any injury requiring first-aid treatment or greater care, or any incident resulting in more than $25 damage to the bicycle. Of those riders responding to the questionnaire (67% response rate), one out of seven (14.8%) were involved in one or more accidents during the summer.

Accident Rates.

Knowing which portion of the trail was ridden by each rider and how many accidents took place, we have established an accident base rate of great accuracy. The participants that responded rode a combined total of 4,998,617.7 miles and experienced 399 accidents. Thus the accident rate is 79.82 per million miles traveled. In simpler terms, a rider in this group is likely to have an accident requiring first-aid treatment or greater attention every 12,500 miles. To simplify the reporting, we asked each accident victim to complete the questionnaire for their most serious accident only. Thus, although a total of 399 accidents were reported, only 308 accidents are explained in detail in this report. Please keep this in mind as you read this accident section. To maintain accuracy, we have given all further accident rates as "accident victims per million miles."

In the paragraphs that follow, a breakdown is made of accident rates by sex, age, region, etc., showing comparisons that identify where and how accidents  are likely to take place.


The average male rode a third more miles than the average female, but the average female had an accident rate 31.05% higher. Women had more multiple accidents and reported more serious accidents than men. Although the cause for the higher accident rate among women is not known, possible factors include: women were quicker to use the additional medical treatment than men for less serious injuries, which may indicate that men ignored treatment in some cases, and, hence, accidents went unreported. Women responded to the survey in slightly higher numbers. It is conjectured that the additional weight of the bicycle and load (panniers) may have proven a handicap to some women, who were, on the average, 15 pounds lighter, and 6 inches shorter than the average man. There was nothing indicating women had less experience than men or were less cautious.


The most vulnerable group was 16-20 years of age. They accounted for 40.9% of all the accidents reported, even though that group represented only 27.2% of the total population. Because this accident rate was so high, it is difficult to determine what other factors may be related, such as education level or previous experience. Riders between 31 and 55 represented the cyclist who has fewer accidents than the average, while those over age 55 had slightly more accidents than the average. There is little indication that the 16-20 age group had less riding experience than the other groups; however, there is strong indication that this group was prone to taking more risks (see profile in preceding section).


The rate for all accidents along the TransAmerica Trail was 60.80 accident victims per million miles traveled. Although most of the states fell quite close to this norm, there were three states that varied markedly.

The two safest states of Missouri (29.49) and Montana (38.45) had rolling or mountainous terrain. Missouri is characterized by very quiet rural roads that are similar across the entire state. Although very rolling and quite steep in sections, the roads were well designed (good visibility, no sharp curves) and were well maintained. Potholes are very rare. Most drivers were well mannered and courteous. Similarly, in Montana cyclists found the highways to be wide, well maintained, with few turns. Although Montana has a slightly higher traffic count, overall, than most of the states, traffic was seldom a problem due to the wide roadways. Ironically, Montana and Missouri, while holding the lowest frequencies, were the sites of both bicyclist fatalities. The specific causes of these fatalities is discussed elsewhere in this report.

The two most hazardous states along the trail, in terms of frequency of accidents,. were Kentucky (101.48) and Virginia (63.77). Kentucky's roadway system is dramatically different from that of Missouri. In the state of Kentucky, there is a definite difference between the topography west of Berea (Lexington area) and the topography east of Berea, where a high rate of accidents occurred. East of Berea the roads are narrow and winding. There are many hidden turns and sharp hills. Terrain is often quite steep. Even more hazardous, the roadways are completely demolished for 30 to 40 feet at intervals as close together as one mile. Eastern Kentucky has many coal trucks that carry their loads at high speeds on roads that the cyclists were forced to share because of the lack of alternative routes. Although most truck drivers were courteous, these vehicles are often overloaded, carrying 30 tons each. The effect of the heavy loads on such rural roads is extreme wear, completely destroying the roadways in major sections. Bikecentennial literature and leaders continually warned the cyclists of the extreme hazards, perhaps holding down the accident rate yet the rate was nearly double that of most other states.

Virginia had a slightly higher-than-average accident rate. Although Virginia had a much better roadway surface than Kentucky, poor visibility and sharp turns with steep descents occurred through much of the state. Dense foliation also cut down on the overall visibility.

Two additional areas demanding concern for safety were Yellowstone National Park and the entire state of Wyoming, where traffic counts were often above 1,000 ADT. It is felt that the extreme care taken by the officials of Yellowstone National Park and the Wyoming Highway Department helped prevent many potentially serious motor vehicle/bicycle conflicts. In Yellowstone precautionary steps included handouts to all motorists notifying them of the correct procedure to pass bicyclists and a requirement that extension mirrors for vehicles towing trailers must be removed any time the trailer is not being towed, and frequent radio announcements over the special park radio station. The state of Wyoming posted large (8' wide) special warning signs every several miles and patrolled the highways frequently.

Cyclists Carrying Equipment.

One surprising comparison is the great difference in accident rates between bicyclists riding unloaded and loaded bicycles. Those riding with packs and equipment (bikepacking) experienced nearly three times as many accidents as those riding an unloaded bicycle. Unfortunately, nearly 85% of all riders packed equipment. The accident victim rate per million miles traveled for each group on the trail was:

Camping groups 83.41
Bike-Inn groups 61.02
Independent cyclists 62.76
Full Service (no equipment) 22.23

The full-service group riders rode the same portions of the trail as others with equipment. The only difference, outside of having an unloaded bike, was a slightly different group profile. However, the profile was similar to other short-tour groups that carried equipment and experienced the higher accident rates.

One possible cause of the 250+% increase of accidents among riders carrying their own equipment was the different responsiveness of a bike under a load. A heavily weighted rear wheel tends to unweight the front wheel, reducing the tracking power and steering action of that tire. An unweighted front wheel can slide out from underneath the rider on gravel. Higher downhill speeds are common, and objects such as potholes are not nearly so easily steered around. In short, the loaded bicycle is less responsive and may actually cause the rider to take a greater number of falls in tight situations. Other causative factors include carelessness in packing the bike, faulty saddlebag or handlebar bag design causing items to fall into the wheel, and overload of a bike design (lightweight 10-speed) not suited to transport heavy loads. Although the 10-speed may structurally handle the added stress, the design may be inappropriate to the new riding style that must be mastered. Further study of loaded versus unloaded bicycles is recommended in order to reduce the number and severity of accidents.

Major Causes of Accidents.

Walt Kelly, creator of the famous comic strip character Pogo, could just as well have been describing the major cause of accidents on the TransAmerica Trail when he wrote, "We have seen the enemy and he is us!" The largest portion of the accidents (20%) involved bicyclists colliding with bicyclists. In fact, the next greatest cause, potholes and broken pavement, accounted for only half as many accidents. A majority of these bike/bike collisions resulted from one bicyclist tailing another too closely. This practice, known as "drafting," or "taking a wheel," is often done to reduce the air resistance, especially on a windy day or at high speeds. Although the technique can be used effectively by skilled riders, it requires great attentiveness from all riders and is much more difficult with heavily loaded bicycles which are less responsive. Other causative factors include riders stopping in the road or an unannounced movement by one bicyclist to avoid debris or a pothole.

A contributing factor to this situation may have been the small group format of the Bikecentennial trips. A buddy system, where one rider was expected to ride within sight of another, was encouraged throughout the trail. In addition, the social aspect of group riding kept many riders close together. Although this may have helped in the reduction of serious accidents between motorists and bicyclists, it may have increased bike/bike accidents.

Potholes/Broken Pavement.

The second greatest contributor to accidents (10.7%) was the presence of potholes and breaks in pavement. Although a fair percentage of these hazards can be avoided by keen eyesight, attentiveness, and quick reflexes, such obstacles pose a very real and serious hazard to bicyclists, especially on downhill stretches where increased speed and reduced reaction time combine to catapult the rider into a hard and serious fall.

Motor Vehicle Accidents.

Motor vehicles were involved in two kinds of accidents--those in which a bicyclist was hit or ran into a motor vehicle (10.4%) and those in which a bicyclist was "brushed," "blown," or "frightened" off the roadway (7.1%). Together these incidents accounted for 17.5% of all the accidents on the trail, and 50% of these required more than first-aid treatment (as opposed to 40.5% average of all accidents). Both deaths, as well as the majority of the serious accidents, involved motor vehicles. Because of the seriousness of motor vehicle accidents, an entire section of this report is devoted to this cause of accidents.


Loose gravel on paved roadways accounted for 5.2% of all accidents. Gravel is often found as debris at intersections, on curves, in areas of light road repair, and where driveways enter the highway. Gravel-related accidents are more common on downhill descents and far more serious because of increased speed. About 2.1% of the total distance of the trail was on all-gravel (unpaved) roads. These gravel roads accounted for 2.6% of all accidents. The narrow tires of the lightweight 10-speed bike are more susceptible to damage and more difficult to handle on gravel than the larger tires once standard. Very few of the riders felt comfortable riding on gravel roads, and many chose alternate high-traffic roadways where more serious and frequent injuries occurred.


Although only about 15% of the TransAmerica Trail is steep enough to be thought of as a downhill, a full 38% of all accidents took place while riders were making a descent. In fact, downhills accounted for between 50% and 75% of the accidents in each of the following categories:

  1. Bike hit hole.
  2. Bike skidded and crashed.
  3. Rider fell off.
  4. Bike hit animal.
  5. Loose gravel on pavement.

Downhills also accounted for 80% of all fractures and most lacerations. Because of the frequency arid severity of downhill-influenced accidents, it is suggested that major emphasis be placed on this added hazard. Especially steep descents should be marked, gravel and potholes should be eliminated, and bicyclists should be advised of the potential of taking a serious fall.

Time of Day.

Analysis of time of day failed to reveal any peak periods. Allowing for a slightly higher rate for periods in which most bicyclists would be on the road (10:00 AM through 3:00 PM), the pattern of accidents remained fairly uniform. There was no indication of a greater rate of accidents during the first hour of riding or during the heat of the day. However, a significant increase in motor vehicle-related accidents took place during afternoon and late afternoon hours (see section on motor vehicle-related accidents).


Fatigue may have played a major role in accidents of trips involving daily rides exceeding 70 miles. For persons who planned rides of over 75 miles in one day, 75% of the accidents occurred after they had ridden 70 miles. In contrast, bicyclists riding shorter daily distances did not experience a sudden rise toward the end of their mileage for the day. This suggests fatigue was an important factor for those who rode distances beyond 70 miles in one day.

Accident Reporting.

Although the zero deductible medical plan encouraged reporting of accidents, 67.6% of all accidents went unreported to either the insurance company or police. Approximately 10% of the bicyclists reported their accidents to local police departments. Those accidents most often reported included motor vehicle accidents and injuries requiring medical or hospital treatment. Accidents requiring no more than first-aid treatment are rarely reported.

Bicycle/Part Failure.

Bikecentennial riders were asked if malfunction of a specific part of their bike caused the accident. Out of the 308 accidents, 21 have been ascribed to part malfunction. Of these, 5 were attributed to brakes, 3 to forks, 2 to cranks, 3 to chains or derailleurs, 5 to panniers, handlebar bags or carriers, and 3 to wheels. Further study is needed to determine if these accidents are related to product design and manufacturing or to poor maintenance. Many accidents were attributed to faulty design of panniers and handlebar bags, which might break loose on a downhill descent and jam the wheel. Of even greater concern is the marked rise in accidents (nearly triple) of those using lightweight bikes to carry 20-40 pounds of camping .gear. Additional study is needed to determine the best design for bikepacking type bikes.

Roadway Condition.

A dramatic 59% of the riders reported that the roadway condition was a factor in the accident. Of these, 35% listed bad shoulder as the factor, 20% gravel conditions, 16.6% potholes, 10% wet/slippery conditions, and 7.0% debris. Bumps, uneven pavement, sharp unmarked curves, and rough railroad crossings made up the remaining miscellaneous factors.


The average speed at the time of accidents was 12-14 mph. In contrast, the average speed of all the riders throughout the summer is reported at 11-I3 mph. Although there is not a marked difference in speed, the more serious injuries are tied directly to greater speed. For example, those cyclists who suffered cuts while traveling less than 15 mph were less likely to require stitches than those who were traveling at more than 16 mph. Sixty percent of the riders who suffered fractures were traveling at a rate of 16 mph or greater. One out of four of the accident victims reported they were traveling above their normal speed at the time of their accident. Thus, although higher speeds do not appear to be a major cause of accidents, speed increases the likelihood of a more serious injury, and suggests a greater rate of accidents. Actual speed may not be as great a factor as the loss of control experienced by traveling at a higher rate than normal for the rider. The higher speed of more youthful riders seems to be a factor in their greater-than-average accident rate.


In analyzing the severity of injuries we learned that falls from a bicycle resulted in the most severe injuries. Hospitalization was required more frequently when the bicyclist was hit by a car, the rider fell off, or the bicyclist hit an animal.

Severity of Accidents. Accidents were classified according to treatment of injuries. Those requiring no first aid or medical attention were considered the least serious, and those resulting in permanent injury or death as the most serious. A breakdown by classification appears as follows:

(Note: Figures exceed 100% due to use of multiple questions.)

No Treatment Required 13.0%
First-Aid Administered 59.1%
Additional Medical Treatment 35.7%
Length of Hospital Stay:  
  a) Does not apply 70.4%
  b) Released same day 20.1%
  c) Overnight stay 01.3%
  d) 2-3 days 02.3%
  e) 4-6 days 04.2%
  f) 1-week or longer 00.6%
Permanent Injury 06.2%
Death 00.6%

(Above figures based on 308 most serious accidents out of 399 reported.)

Permanent Injuries.

Out of the 399 accidents reported during the summer, 19, or 6.2% resulted in a permanent injury. Of these, 16 were severe enough to prevent completion of the trip. The greatest percentage of-permanent injuries involved injury to the head or face. Since the respondent used his/her own judgment in listing an injury as permanent, a portion of these 19 injuries may be moderate, limited to a major scar, slight disfigurement, or minor nerve loss. Of these permanent injuries, our best judgment leads us to believe that roughly one out of four injuries was severe enough to be considered disabling to any degree. Disabling injuries included partial loss of hearing, some restriction in limb movement, or severe loss of limb movement.


During the operation of the trail in 1976, two cyclists were killed by overtaking motor vehicles. Further details of these incidents are presented in the special section on motor vehicle accidents.

Accident Costs.

Another opportunity of this study was a complete analysis of the costs associated with the accidents. Bikecentennial contracted a major medical insurance company to underwrite all participants with a zero deductible accident/health plan for all illnesses or injuries up to $1,500 per incident. Although the zero deductible plan may have encouraged many bicyclists to seek treatment for relatively minor injuries such as cuts and scrapes, the plan obviated non-treatment that may have led to serious infections or permanent scars. It is interesting to note that along portions of the trail quite distant from a hospital, relatively few bicyclists sought treatment beyond first aid. Thus areas near hospitals showed increased accident rates. A breakdown of cost percentages appears as follows:

Accidents resulting in medical costs under $25 16.2%
Accidents resulting in medical costs under $50 93.2%
Accidents resulting in medical costs exceeding $300 3.6%
Accidents resulting in property losses under $50 88.0%
Accidents resulting in property losses over $100 7.8%

Accident damage to bicycles occurred in 55.8% of all cases, and other property loss in 11.7% of all cases.

Types of Injuries.

Most bicycle injuries include a fall at moderate speed (8-15 mph) resulting in sliding or tumbling along the road or road edge. Since much of the riding occurred on warm days, bicyclists wore very little protective clothing. The reported injuries by type are listed below:

Non-Injurious 7.9%
  Cuts and Scrapes 51.0%
  Bruises 13.0%
  Sprains 4.9%
  Lacerations Requiring Stitches 7.2%
  Fractures 3.3%
  Concussions 3.3%
Fatal .6%
Miscellaneous/Multiple Injuries 11.8%


Although this concludes our coverage of data on accident severity and causation along the TransAmerica Trail, it serves only as an overview of the real and serious nature of bicycling accidents. These other important facts were uncovered. Bicycle accidents are almost always multiple caused. Poor road design, inattentive riding, or high-volume traffic do not by themselves lead to an accident; however, a combination of two or three factors makes an accident more likely. It is our belief that as many as 70% of all trail accidents could have been avoided, with greater knowledge and care by bicyclists. Bicyclists in the 16-20 age group need to understand the very special risks they encounter because of their riding style. All bicyclists need to be aware of the nearly tripled accident rate when riding a fully loaded bicycle. The likelihood of bike/bike collisions should be explained to those who plan to ride close together. The added risk of downhill riding is evidently not obvious enough to those riding mountainous terrain.

Roadway design and maintenance improvements, we believe, could also help prevent many accidents. Debris, potholes, lack of-adequate shoulders, unmarked hazards, and gravel on paved roadways should be eliminated in all areas of frequent bicycle traffic.

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