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Accident rates varied as much as 300% between different roadway conditions along the TransAmerica Trail. This single bit of evidence, backed up by other statistics on where and how accidents occur, lead us to believe that one of the most effective ways of reducing bicycling accidents is to locate and promote the use of lightly traveled roadways that meet safe bicycling design criteria. In this section of the report, we discuss the criteria found most helpful for reducing roadway influenced accidents, the need for maintenance, liability problems, and a list of route characteristics cyclists prefer.

Rate of Roadway-Influenced Accidents.

As discussed earlier in this report, accident rates varied from a low of 29.4 accident victims per million miles traveled in Missouri to a high of 101.5 in Kentucky. A few areas had estimated rates of more than 1,000 accidents per million miles. Bicyclists left the trail occasionally in favor of faster or better-paved roadways. Although off-trail riding was estimated to be only 2.6% of the trail length, 18.6% of all accidents during the summer took place off the designated trail. Other evidence that use of casually selected highways leads to greater accidents includes the following: '

  • Jerry Kaplan's (FHWA) study of League of American Wheelmen (adult) cyclists in 1975 showed an accident rate of 113 accidents per million miles. This contrasts with 79.8 on the TransAmerica Trail.
  • At least 3 deaths and 20 serious injuries were reported to Bikecentennial as having happened to bicyclists using casual routing to or from the trail. These accidents were not included in the data base for this report.

Design of the TransAmerica Trail. The TransAmerica Trail was developed over a three-year period, requiring the cooperation of 10 states and more than 90 municipalities. The work was coordinated by Bikecentennial and was based on criteria established through work with the Federal Highway Administration, U.S. Department of Transportation; Bureau of Outdoor Recreation, U.S. Department of Interior; and several private research and user groups. A complete description of the criteria is given in the Appendix. In many areas the, trail was not ideal. Whenever possible, the roads incorporated as many of these specifications as practicable: low traffic volume (below 1,000 ADT's); smooth unbroken pavement, clear of potholes, bumps, or debris; maximum road width; road edge blends with paved shoulder; good visibility; low volume of cross traffic; gradual grades and curves; area of low urban development potential; attractive scenery; easy access of nearness to centers of great population; Popularity with local bike club; and direct route.

It was difficult to apply the above criteria to a route spanning the entire nation. Several of the criteria, such as "near centers of great population" and "low traffic volume," are contradictory; and we preferred the low traffic volume. As much as 2.4% of the trail is on gravel roads to avoid heavy traffic. To give insight into which of the design criteria are most suited to the wants and needs of bicyclists, our survey included specific questions on design preference.

Cyclist Preferences.

In order to learn what hazards are of greatest concern to bicyclists, we included in our survey questions regarding road conditions, specific hazards, and vehicles. Note the difference between perceived hazards and actual percentages of accidents. The hazards are listed in the order in which they were perceived by the cyclists, and the percentages indicate the actual frequency of accidents caused by these hazards.

  Road Condition (Frequency) Other Hazards (Frequency)   Vehicles (Frequency)
(1) Broken Pavement


Railroad Tracks 1.6% Recreation Veh


(2) Gravel on Pavement


Animals 2.0% Tractor-trlr .


(3) Gravel Road .

2 6%

Cattle Grates   Automobile


(4) Unmarked Hazard   Bridges   Other


(5) Debris   Tunnels   Local Trucks  

High-Volume Traffic.

Of great concern to most bicyclists is the noise, pollution, and nervousness accompanying having to share roadways with large numbers of cars. To indicate just how serious bicyclists were about avoiding such roadways, Bikecentennial riders were asked to choose among alternatives. Their responses appear as follows:

Hills. To bypass a busy roadway section of 25 miles, 81% of the respondents would use a less-traveled roadway that had 10 to 30% more hills. In support of this, most bicyclists preferred the mountainous terrain of Oregon, Idaho, Montana, Wyoming, Colorado, Missouri, Kentucky, and Virginia to that of Kansas. Varied terrain adds dramatic variety to a route without appreciably slowing the rider. Novice bicyclists, or those using a route for commuting or utility use, may not seek such variety.

Distance. To bypass a busy roadway section of 25 miles, 89.8% of the riders would use a less traveled roadway that added 5 miles to their overall mileage. Again, utility or commuter bicyclists may not choose such an option.

Gravel. In order to avoid a busy roadway section of 25 miles, cyclists would travel a gravel roadway as follows:


would ride 5 miles on gravel


would ride 3 miles on gravel


would ride 2 miles on gravel


would ride 1 mile on gravel


would not ride on gravel

It is interesting to note that, despite a serious aversion to gravel roads by most riders, traffic is of enough concern for them to consider up to 1 mile of gravel. Sections of gravel along the TransAmerica Trail were ridden by as few as 10% of the riders , although it was clear that the alternative paved roads were far more hazardous because of high traffic density.

Preferred Roadway Improvements. The best improvement to a busy roadway was selected as follows:

Identify Bike Lane 52.3%
Separate Bike Path


Widen Pavement


Reduce Speed to 5 mph


One of the most acceptable heavily traveled roadways in North America is the Canadian National Park road between Jasper and Banff National Parks. Two full lanes of one direction traffic allow the motorist to use one lane for travel and another for stopping. The right lane is ideal for bicycle traffic, offering exceptionally low risk to both users. An adoption of this system might be workable in short sections of a route where high auto and bike traffic are common, such as along U.S. Route 101 on the Pacific Coast. Such routes would need periodic removal of debris for maximum safety.

Road Conditions. A coarsely paved 25-mile stretch with some potholes, but deserted of almost all traffic is preferred over a smooth, well-maintained road that has heavy traffic by 88.4% of all riders. Again, cyclists fearing the great hazard of motor vehicles along with noise, pollution, and anxiety, would prefer a slower, less-maintained roadway. Further reinforcing selection of the more typically rural roadways, 95.6% of the cyclists prefer rural roads with little traffic and with only occasional services available to a roadway with frequent services but heavy traffic. And 87.2% of the cyclists preferred a route that meanders through quiet back country and occasionally returns to dramatic geography such as the Pacific Coast for short 20 to 70 mile stretches, as opposed to 11.9% who felt they could cope with 500 miles of moderate-to-heavy traffic on a route that hugged such dramatic geography.


One of the most significant-factors in the development of the TransAmerica Trail was the success of the Bikecentennial organization in eliciting participation by 8 of the 10 states in placing bike route signs along the trail. Missouri approved the signs but was unwilling to bear 100% of the costs and hence did not post them. Idaho claimed liability to be a problem and avoided signing. The bike route signs in use provided route verification for cyclists and notified motorists that they were sharing the road system. Wyoming used an impressive large warning sign cautioning motorists and cyclists. This sign is credited with having reduced the potential conflict on several sections of especially hazardous roadways.

When the cyclists were asked how important bike route signs were to them, 6.1% said they were not significant, 34% felt they provided information use only, 35.9% felt there was some safety benefits derived from their use, and 22.9% felt that signing the route was a major safety benefit.


The question of signing, approving, or encouraging use of specific roadways for bicycling is of growing concern to many states. As mentioned earlier, 27 states have now incorporated Bikecentennial design criteria in selecting a bike route. Many highway departments are concerned with the question of liability, especially in light of eroding sovereign immunity. States, and local units of government are being sued for negligence and many of them are losing.

Generally, the agency responsible for the care and maintenance of highways is required to construct safe thoroughfares and keep them that way. The highway user should expect to travel that thoroughfare in a safe and efficient manner without having to search or be on guard for unseen hazardous conditions. He should not be caught unawares or be expected to anticipate dangers to which his attention is not directed.

Subsequent to proper design is a maintenance and inspection program to provide safe highways. Should unsafe conditions be discovered, it is the governing agency's responsibility to alert highway users to the condition prior to and during the elimination of the hazard.

State law concerning liability for signing, road improvement, and maintenance varies widely from one state to another. These laws are created primarily by court decisions in response to individual controversies rather than by statute. It is safe to say, however, that state liabilities for design effects are increasing, and that the state may not always avoid liability by doing nothing. A state may be found to be negligent either because it signs roads improperly or because it does not sign them at all. The use of potential liability as an excuse for not providing signs is usually to avoid admitting what the state does not want to do in any event.

Several states on the TransAmerica Trail still retain absolute sovereign immunity, steadfastly refusing to modify or waive it without clear legislative authority. Three such states are Virginia, Missouri, and Wyoming. Colorado has a representative body through which citizens may seek redress for the state's negligence even though that state retains sovereign immunity.

A major development in the field of signing for bicyclists is now taking place. The National Advisory Committee on Uniform Traffic Control Devices had adopted two new parts for publication in the Manual on Uniform Traffic Control Devices. Part VIII, entitled "Traffic Control Systems for Railroad Crossings," was adopted in October of 1976. Part IX, entitled "Traffic Control for Bicyclists," was adopted January 21, 1977, and was scheduled for publication in the spring of 1977. Publication of the latter section will go a long way toward standardizing the field of bicycle route designation.

Roadway Classifications. Whenever possible, Bikecentennial routed the trail along quiet rural roads. In major sections of the nation this was difficult or impossible. An estimate of the relative percentages of roadway lengths ,by classification is as follows

Federal Primary. 25%
State Primary 28%
State Secondary 24%
County 23%

Bicycles on Controlled-Access Highways.

Of the 4,212.2 miles that make up the TransAmerica Trail, 21 miles are part of Interstate 80 between Rawlins, Wyoming, and the Walcott exit at State Route 130. I-80 is a four-lane freeway with medium-to-heavy traffic. Two accidents occurred on the interstate; both resulted in sprains to the riders. One rider caught his tire in a crack between the road and shoulder while traveling over 30 miles per hour. The fall resulted in a sprained wrist. The other injury occurred as a vehicle swerved into the shoulder of the interstate, brushing the cyclist. The rider fell with both feet still in his pedals and toe clips and sprained his left arm or hand. The accident rate for this stretch of highway was the same as the average for the trail--one accident for every 9.4 miles ridden.

At present various states take different positions with respect to whether or not bicycles are prohibited or allowed on controlled access highways. Of the ten states that contain part of the TransAmerica Trail, five have taken positions relative to allowing or prohibiting bicycles on controlled access facilities. Colorado allows bicycles inside the right of way, but only on separate pathways. Wyoming allows bicycles on the shoulders of the interstate. Montana encourages use on interstates rather than the narrower service roads. Idaho is considering prohibiting bicyclists from using interstate highway shoulders because of the danger from passing trucks. Oregon permits bicycles on controlled access facilities, except where they are prohibited in the Portland area.

Bicycle travel on the shoulder of interstate highways is feasible but should be examined on a state-by-state basis for safety and other considerations, including availability of alternative routes. The wide shoulder provides the cyclist sufficient room to avoid buffeting winds from large vehicles. A disadvantage of interstate riding would be the high volume of debris that collects on the shoulders and the noise, pollution, and tension posed to the bicyclist. Cyclists permitted to use interstate shoulders should be required to exit at each ramp in order to avoid conflict with motor vehicles.


Routes planned to take bicycle traffic and kept in good maintenance can reduce bicycling accidents dramatically. Although many bicyclists would strongly oppose being prohibited from particular roadways, the great majority would prefer safer, more tranquil back roads that are properly maintained. Such action would lead to improved traffic flow on all highways and encourage safe, convenient bicycle travel. Improving the design of unlimited access roads for bicycling and assuring proper maintenance would benefit all highway users. Most bicyclists will not find these safer roads uninformed. Local and state agencies can assist their efforts by locating and posting such preferred routes. Such a program should include improvements in signing and road repairs to reduce one of the primary elements of bicycling accidents.

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