Yellowstone Historic Resource Study The History of the Construction of the Road System in Yellowstone National Park, 1872-1966

Frank E. Mattson
Landscape Architect
July 1951

SUMMARY

The objective of increasing or improving our road standards has been made to provide a wider and safer road and to provide such dimensions as will permit roadside parking so that the park visitors may slow down in safety and stop to view the wonders of the parks. The recent and current roads section designs, although directed toward such ends, do not result in these objectives. The practice of giving the road shoulder a bituminous treatment is actually increasing the width of the traffic surface beyond the desirable dimensions and not increasing the width of the shoulders and in many cases eliminating the shoulder entirely. Reprocessing the traffic surface during maintenance operations is resulting in wider and wider traffic surfaces and eliminating an effective shoulder. Many traffic surfaces now compare with the hazardous three lane widths.

The wider traffic surfaces are conducive to speed. Greater and faster speeds with more powerful cars in areas where we wish to keep the speed down to a minimum for no other reason than for the benefit of the park visitor. The road shoulders which we hoped to attain are not materializing and we provide for no roadside parking strip to permit the visitor to pull out of the traffic lanes to view the scenes of the park.

Our design standards, patterned upon State highway work is headed in the wrong direction. The standards of roads within the parks do not necessarily need to comply with highway standards outside of the parks and moreover the parks, of necessity, should have standards of their own.

Road shoulders are required in National Parks and they should be at least five or six feet wide to adequately serve slow moving and stopping by the park visitors. However, with the Services' background in conservative road widths, we do not feel free to recommend such wide road shoulders. It would be well if someone could have the vision to promote wider road shoulders.

Road shoulder design should fit the terrain. Generous widths are desirable and permissible in open and rolling terrain while lower standard overall dimensions should be used on mountainous terrain.

The traffic surface of park roads does not need to be more than 22 feet.

Maintenance operations need to be keyed to the standard to which the roads have been constructed. This rule should apply to modern sections. On unimproved sections some programmed improvements may be necessary with maintenance.

The term traffic surface is used here to describe those portions of the road surface which are designed to carry traffic and also those portions which will carry traffic because of their appearance and construction. Road shoulders, as we describe them, will be those portions of the road outside of the limits of the traffic surface. In other words, a traffic surface does not or is not described as having a shoulder.

During the discussions with the Bureau of Public Roads in 1946 while attempting to give our road program a long look ahead in preparation of the Road Report and without the benefit of the Services' consolidated thinking, it was the consensus in Yellowstone that we propose a road section with 22 feet of traffic surface and the equivalent of 4 feet of shoulder on a common plane with the traffic surface. Since the Bureau had already prepared their estimates on the basis of a 28 foot grade Mr. Learned requested that we retract this proposal to 3 foot shoulders, which we did. The Bureau also advised us at the time that the other areas of the Service were much more conservative. In our efforts to arrive at road shoulders on a common level with the traffic surface we agreed to shoulders which sloped away from the traffic surface on 12-1 as that would be quite an improvement over what we now have. We still believe that the shoulders should and can be on the same level as the pavement. The oiling of the road shoulders was not discussed at that time. All new road designs in the park propose the oiling of the road shoulders which we believe is undesirable for park roads.

RECOMMENDATIONS

GENERAL

Retain the standards we now use for flatness of slopes and fills and for rounding and warping of cuts and fills. Consider the steepening of shallow fill slopes to discourage rather than encourage driving off the roads. Provide extra road widening where it comes easily without moving deeper into hillsides, such as small daylighted outside cuts.

Provide 22 feet of traffic surface on all roads and stay within that dimension.

Provide shoulders which are on a common plane with the traffic surface.

Use shoulder material which will permit the growth of grasses and be stable enough to support traffic.

Eliminate the ditching on dry terrain where it actually serves no purpose.

Where moist conditions prevail consider extra subsurface drains in preference to heavy ditching.

Conventional standards for widening on curves and compensation for grade and alignment and for access roads should be followed.

FOR OPEN AND ROLLING TERRAIN

In Yellowstone:

Provide 3 foot shoulders for all Entrance and Grand Loop Roads.

On presently constructed roads which are considered complete this would mean reconstruction to provide for shoulders. On proposed improvements and on new construction it would mean redesign of the section to provide for shoulders which do not become absorbed into the traffic surface.

In Grand Teton:

The Eastside road for through traffic; provide four feet shoulders.

The Jenny Lake road: Retain as near as possible its present character.

Present Westside through road; 3 foot shoulders.

FOR MOUNTAINOUS TERRAIN

Some traffic width with no shoulder on the inside but with a small paved ditch. Generally no shoulder on the outside except to support traffic surface and guard rail where necessary. Provide wide shoulders, 4 feet if practical where location and terrain will permit, such as in through cuts on the outside of curves.

FOR MAINTENANCE

Maintenance should conform to the designed and constructed standards and not modify any standards unless they are programmed and authorized. Sections not conforming to design at present should be corrected to comply such as the South Approach road directly south of the park boundary.

PRESENT TREND IN CROSS SECTION DESIGN NOT DESIRABLE

The Rocky Mountain region has road cross section design which in a number of respects is peculiar to this section of the country. The section consists of successive layers of base or surfacing material for the traffic surface superimposed upon the rough grade leaving a traffic surface of about 22 feet above sloping road shoulders when the graded width was great enough, and no shoulder to mention where the original width did not permit it. This method lends itself to a simple type of road construction operation permitting various phases of the improvement to be accomplished over a period of years. In fact, in some respects, it permitted the stepping up of standards during the period in which the road was built. This is apparently what happened in Yellowstone, resulting in roads which have no more than a traffic surface and no supporting shoulder and no parking shoulder.

Through these stages the place has been reached where it is generally agreed that 22 feet is an adequate traffic surface width and we have followed this standard in the park, although, all of the road do not meet that dimension the State of Montana is going to 24 feet traffic surface dimensions, but 24 feet traffic surface alone with no shoulders is not adequate for safe driving.

On most of the park roads the traffic surface alone is the entire road width and for this reason there have been constant proposals to widen the roads. The standards have been raised in graded width and there are plans to improve already graded and partially surfaced sections. What are these plans like? Will they give us the wider roads we have been wanting?

All of the newer plans including those already graded and based show the paving of the shoulders and in some cases the ditches. This is a practice which the states have employed and evidently its objectives where admirable. It was hoped that the bituminous treatment would hold up the shoulders and it was also hoped that a differentiation could be provided in texture and color to show what was traffic surface and what was shoulder. We began following these principals in the parks but possibly not for the same purpose. The section appeared to have a facility for not requiring as wide a construction section.

However, the end result, and it can be observed on practically any of the bituminous surfaced highways in recent state work and in the park from Old Faithful to Isa Lake and on the South Approach Road, is that we have a wide traffic surface and no shoulders of consequence; no shoulders on which one would feel free to park and be free of the hazards of passing traffic. Without extremes in construction and maintenance costs we do not believe that it is possible to retain any difference in color or texture of the shoulders and traffic surface. Furthermore, there is proof that vegetation is more satisfactory for the prevention of erosion than a bituminous treatment.

The habits developed by maintenance work is reprocessing edge to edge currently resulting in 26 foot to 30 foot traffic surfaces were not, we believe, intentionally directed that way. But we do believe it is a serious mistake to continue the practice to provide that much traffic surface and wipe out the shoulders entirely. The object of the present cross section design and the object of the gradual increase in standards was to provide a road shoulder. The trouble with the paving methods is that we end up with no shoulders. The pride in squeezing 27 feet or 28 feet of surfacing onto a grade could very well be directed toward a constructive approach in retaining the original design of the section. The actual approaches to three lane highway dimensions is enough to terrify some of us.

Therefore, within the parks, all of us have urged the necessity of road shoulders so that traffic can flow smoothly while the visitors slow down or stop to view the wonders of the parks. We have built a number of sections with that particular improvement in mind. Now that they are built what do we have?

The trend of the design, the construction of the grade, and the actual maintenance of these sections has resulted in greater traffic surface widths and we still do not have any road shoulders. The trend is toward progressively wider traffic surfaces and narrower shoulders. The wider traffic surfaces are encouraging speed on roads which were not designed for speed.

PROGRESS IN ROAD DESIGN IN YELLOWSTONE

We believe that a review of the gradual improvement of the standard within Yellowstone will illustrate very well the pattern which we are now following.

THE STAGECOACH ROADS

There are several sections of road still existing which have not progressed far since they were built for stagecoach use. Although narrow, they are relatively safe because of the enforced slow speed, due to alignment standards and site distances. They do not have any shoulders but the fact that they also do not have any ditches permits a certain amount of freedom not found on many of the improved sections.

CIRCA 1927

The portions of the road on the north section of the loop and part of the East Entrance which were rebuilt during the first phase of reconstruction were on a relatively lower standard of grade compared to that which we are using today. Consequently, as the roads reached the stages of construction when the base and surfacing was being placed, the standards has been increased to a degree where the objective was to provide 22 feet of traffic surface. With the successive lifts of base and paving this width was attained in some cases but as on the Dunraven road it remained at 20 feet. The fact that this left the road without any shoulder was quite unavoidable and for this reason these sections of road, namely: Canyon-Tower Junction, Mammoth, Norris, Madison to Firehole Cascades and the east end of the East Entrance are now considered narrow for park use. They need to be improved. Even with maintenance it is not very practical to rebuild shoulders where none existed before. Reprocessing of surfacing on these sections has been an edge to edge operation and it cannot very well be much different.

1932-1936

The standards of this era were 26 feet graded sections for entrance roads and 28 feet graded sections for loop roads. They were designed for 22 feet of traffic surface which was superimposed upon the base course, which in turn had been superimposed upon the 26 foot or 28 foot grade; which did not leave much road shoulder.

The Northeast Entrance to Lamar section is a good example of what has resulted without disturbing the original construction. This was especially noted when Messrs Vint, Hall, Kreuger, and Cabot arrived in the park. Other sections with this standard within the park are: Firehole Cascades to Old Faithful, Isa Lake to West Thumb to Arnica Creek, Bridge Bay to Lake Junction, Lake to Canyon, South Entrance to Thumb. Reprocessing of unbased sections leaves traffic surfaces in the neighborhood to 27 feet wide. Reprocessing of finished sections leaves edge to edge traffic surfaces.

1938 TO PRESENT DATE

The sections built, such as Old Faithful to Isa Lake (see below) now show a definite trend toward completely roofed surfaces. This practice is in the plans for a number of portions included in the above construction period. Those portions include the Canyon Area, Northeast Entrance (Lamar to Tower Junction), Lewis Lake to Thumb, Lake to Canyon and the South Approach Road. With the exception of the South Approach road which is 30 feet wide these are all on 26 foot and 28 foot grades. The proposal is to give all of the shoulders a bituminous treatment although the traffic surface theoretically is designed to remain at 22 feet. Reprocessing of the first constructed portion of the South Approach road the past month has resulted in traffic surfaces in the neighborhood of 28 to 30 feet wide.

Incidentally, the South Approach Road dimension is measured on the grade after 4 inches of select material (which for all practical purposes is 4 inches of base) has been placed. This section, therefore, gives us the widest constructed sections we have in this area. The design calls for 22 feet of traffic surface and the balance, out of approximately 28 feet, in shoulder. This shoulder will be sloped if the plans are carried out. Please note again that the current reprocessing of the 1948 constructed section of the road has been spread to 28 to 30 feet wide.

THE OLD FAITHFUL TO ISA LAKE SECTION

Since this road section is held by many people to be an example of the type of road we should build we are making special mention of it. For those who are not familiar with it, it has a completely roofed section. The paving of the traffic surface was laid down separately from the shoulders with 3/8 inch chips and the shoulders and ditches with 3/4 inch chips. Actually this means nothing to the driver and is hardly discernable to those who are supposed to know the difference.

As with the section adjoining to the east of this it is all in relatively rough terrain which has not permitted grades or alignment of a high speed design. Site distances are very short and normally passing or overtaking traffic would not be easy. However, the fact that there is an apparent traffic lane of 28 or 30 feet makes the possibilities for speed obvious and the need for overtaking greater. The chance for passing, because of the wide surface, entreats many to pass who should not take the chance, but since there is width there for maneuvering, the speed is kept up.

Most of us compare this section with those roads in the park which have no more than 22 feet of traffic surface with no shoulders. It is quite natural that this section is considered by many to be a decided improvement over the narrow roads we have.