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Historic Roads in the National Park System
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Teamwork/Cooperative Efforts
Understanding and Managing Historic Park Roads
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Historic Roads in the National Park System
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| PART I: HISTORY |
TEAMWORK/COOPERATIVE EFFORTS (continued)
THE DEVELOPMENT OF ROAD STANDARDS
Some ideas about park roads had been readily adopted by the professional design staff of the National Park Service. Frederick Law Olmsted, Sr., for instance, suggested a one-way loop road for the Yosemite Valley during the 19th century. Also separation of traffic paths by type of use in national parks was helpful, such as main park tour roads, bike or auto trails, and fire roads/truck trails. The road and trail systems at Acadia and Shenandoah were built following that principle. At Acadia the well-landscaped carriage roads were built at different grades and along different paths than the main park tour road. Shenandoah had the Appalachian Trail, Skyline Drive, fire roads that led down into the hollows and served primarily as administrative roads for patrolling the boundaries, and separate hiking trails to individual features such as mountain tops or waterfalls. The landscape architects ensured that the resources were always protected from any damage that might occur during construction, and ensured design in harmony with the landscape of the park. So these were all parts of larger systems.
Other issues that the NPS designers readily embraced dealt with the process of experiencing a road or a trail. A feature, such as a river, could be viewed from a variety of different points, so even though it was the same river, the driver could experience more aspects of the river than a single view would provide. Henry Hubbard had suggested decades earlier that a road laying gently on the land disturbed the natural topography as little as possible, while at the same time it simulated the natural surface of the landscape to the greatest extent possible.
Actually incorporating those thoughts into road construction standards was a very gradual process. When the army was constructing roads in Yellowstone National Park in 1883, the standards were simple and practical:
18 feet width road, well rounded up in the center, and provided with suitable side ditches and cross culverts; that all trees be removed for a width of 30 feet; that on side hill cuttings the fill be retained by a dry stone wall, and that an ample ditch be placed on the up hill side at least a rod from the road to catch the snow water and convey it to the natural water courses, and that where there are meadows or marshes that cannot be drained and must be crossed, the corduroy be replaced by a good plankroad. That all culverts be of stone or 3 inch plank, and that all bridges be well constructed of good sawed lumber. [111]
These early standards stressed cutting the road through the woods and building it in such a way to keep it dry.
The first standards written specifically for the development of national park roads were written by landscape engineer Daniel Hull in 1925. His treatise, entitled "Landscape Protection for Road Development in National Parks," concentrated on aesthetics. Hull said that most road building of the time was an engineering science that did not take into account — what he called the "Landscape Effect."
Hull wrote that new road construction should gain the maximum scenic beauty with the least scarring of the countryside. He stated that some places in national parks should never have roads to them, such as Vernal Falls and Nevada Falls at Yosemite, or the upper portion of Zion Canyon approaching the narrows. In his view the topography of the land would determine road location, and in some instances he believed that one-way roads might solve some complex road design issues around national parks. His treatise stressed that the design of roads should aim for maximum scenic vantage points, and that they should be brought in close proximity to natural features while not endangering their native beauty. He believed that adding a view of a spring, waterfall, or rock cliff provided additional interest for the traveler. To him good road design avoided monotony by traversing through combinations of forest and open country, thus using the variety afforded by light and shade and avoiding miles of sameness. Hull also stressed the use of native materials in road construction and the construction of associated landscape features. In short, he proposed exposing park visitors to specific park experiences through sensitive road design. [112]
In 1926 Mather directed Engineer George Goodwin to develop new standards for park roads based on some of the ideas that Dr. Lawrence Hewes of the Bureau of Public Roads had put forth at the superintendents' conference at Mesa Verde in 1925. Goodwin believed that it was impossible to build roads to those standards under the existing budget, so Mather accepted his resignation.
Mather then had his staff work with Hewes to develop road standards and the interbureau agreement between the Bureau of Public Roads and the National Park Service that covered the planning and supervision of road construction in national parks. [113] The standards that evolved for road construction became a cooperative effort between the National Park Service and the Bureau of Public Roads.
By the mid-1920s a number of advances occurred in park road design. Some of the efforts included finding ways to eliminate hazardous curves, switchback, and steep grades. Engineers from the Bureau of Public Roads and the National Park Service worked on details such as drainage, surfacing, and construction of revetments. NPS landscape engineers worked on aesthetics including location, viewpoints and vistas, architectural character, and following the natural contours.
The landscape engineers took into account not only the view from the road during the entire driving experience, but the view of the road itself from other locations in the park. They made every effort to blend the road in with its natural surroundings and to naturalize the landscape following construction through a variety of means. In the joint effort between the two agencies, the designers made advances in road engineering, too. Cut-and-fill operations became more commonly used in maintaining an even grade. Curvilinear stretches with radial curves superseded the tangents that had been used earlier in road construction. The engineers began using superelevations in both roadways and bridges for a smooth driving experience at higher speeds. As the designers progressed into the parkway designs of the 1930s, they also began using a combination of transitional curves based on spirals and superelevations. Most park roads kept to a 5% grade, although some rough park topography dictated 8% grades in a few areas. [114]
Other standards became more specific. In 1934 Landscape Architect Tom Carpenter sketched out a draft of "Approved Procedure for the Carrying out of the Design and Construction of Major Road Projects in National Parks for the Transaction of Business Between the Branch of Plans and Design in the Office of National Parks and the District Regional Offices of the Public Roads Administration." [115]
Although the interbureau agreement contained the general procedures that the two agencies used, problems often arose in their implementation. Carpenter's document provided guidance in how the agencies could work together so that each agency could achieve its goals.
Next, the National Park Service adopted "General Specifications for Forest and Park Projects," Federal Register 50, 1935 edition, with a few modifications to the provisions recommended again by Landscape Architect Tom Carpenter. Some points were minor. The "General Specifications" stated that the engineer would indicate to the contractor the trees and vegetation that needed to be protected from injury during the course of road construction. Carpenter recommended that all trees and vegetation not to be cleared by protected from injury. Carpenter was concerned, for instance, that the obliteration of old roads did not include the use of duff for a cover. His greatest criticism came in the specifications for stone masonry. The 1935 edition of "General Specifications" were far too general. Instead, Carpenter pushed for the use of the 1932 "Specifications for National Park Road Construction." Those stated:
Where rock supply is of blocky types (such as granite, basalt, some limestones, or river boulders) individual stones shall have face heights between eight and thirty inches and face lengths between 20 and 72 inches, the object being to use stones whose average length is 2-1/2 times their height, with a minimum ratio of 1-3/4 to 1. Such stones shall have minimum face areas of 200 square inches, maximum areas of 2100 square inches, and shall average 600 square inches or larger. Stones with more than two right angle corners will not be permitted. Where rock supply is of elongated types (such as stratified limestone, sandstone, shale) individual stones shall have face heights between 60 and 20 inches and lengths between 24 and 90 inches, the object being to use stones whose average length is four times their height, with a minimum of 2-1/2 to 1. Such stones shall have minimum face areas of 150 square inches, maximum areas of 1800 square inches and shall average 400 square inches or larger. Rectangular stones may be used. Exception is made to this in headwall for pipe culverts [where] individual. stones shall have minimum dimensions of 6 x 15 inches, the object being to average the wall with stones, whose wall lengths are 2-1/2 times their wall heights. Selections may be made with as low a ratio of length to height as 1-3/4 to 1, and as high as 3-1/2 to 1. [116]
Carpenter also stated that the new specifications should establish the proportion of weathered and unweathered stones in a project. Also, he wanted the size of the mortar joints to be in proportion to the heights of the stones used. Wider-sized joints should be used with stones of greater height, and the smaller ones used with stones of lesser height. He anticipated that most joints would be from 1 to 1-1/2 inches wide; but that none would be less than 3/4 inch or greater than 2-1/2 inches. [117]
During the evolution of these standards, Tom Vint's shop began producing standardized plans of certain types of road construction details. Some progress had been made on the development of slopes by the mid-1920s, but in 1929 Vint's shop issued cross-sections showing a variety of slopes with rounded tops. The use of these not only reduced erosion and disturbance, but they also added a graceful curve to the landscape, which harkened back to the work of the landscape philosophers such as Olmsted and Hubbard. The tops of the banks had no overhanging "eyebrow" with an eroding bank underneath. Instead the top was rounded off, and the entire slope was naturalized. Prior to construction the contractors or later during the 1930s the CCC crews removed duff from the slope, and then replaced it after construction. This process encouraged the growth of the native vegetation, and assisted in the slope stabilization process.
Additional methods of stabilizing slopes included resodding slopes, installing wooden cribbing, or using concrete cribbing that was later camouflaged by rubble masonry set in the embankment. Road construction and rehabilitation often involved widening the right-of-way and removing some trees along the edge. To relieve potential monotony, road edges often had variations in forest setbacks which gave a gentle, undulating line to the edge. All of these contributed to improved aesthetics of the park road.
During the 1920s and 1930s several types of edging materials were developed for park roads. Log and stone were the primary building materials for guardrails. Between 1929 and 1942 the National Park Service issued several standardized designs for both types of guardrails (see appendix E). The stone guardrail designs included specifications that emphasized rustic masonry: larger stones toward the base of the wall; weathered surfaces to the outside; random patterns; avoidance of straight lines; and blending stonework with the surrounding outcrops. Variations from the simple wall included the guard wall with the crenelated top, used in some parks such as Bandelier. Sometimes individual variations occurred in parks, such as the guardrail at the overlook on the Yakima Park Road (Sunrise) at Mount Rainier, which included large pyramidal shapes mimicking a mountain every 14 feet, or the blocky coping stones that edged the road at Acadia National Park. The walls normally varied from 18 to 24 inches in height, which allowed visitors to look across them and observe the view while they were driving. The masonry specifications called for using different types of stone in different ways. All, of course, used native stone. The log guardrail designs were usually simple — either squared or simply peeled logs — and consisted of a log pier with a connecting log post. [118]
In most instances the structural aspects of bridges were left to NPS civil engineers who coordinated their efforts with engineers of the Bureau of Public Roads. The choice of materials for the site and the design were the responsibility of NPS landscape engineers. During the 1920s bridges such as those at Christine Falls and Narada Falls at Mount Rainier formed graceful arches that incorporated the radial curves and superelevation of the road, the guardrails, and the abutments into masterful structures of native materials that blended with the landscape. Headwalls on culverts received a similar treatment in attention to rustic detail. [119]
One of the most practical aspects of tunnel construction was how much of the landscape could be preserved by the construction of the roadway through the tunnel. In areas such as Yosemite and Glacier, the use of tunnels on the Wawona Road and Transmountain Road respectively minimized damage to the landscape that excavation for the road would have required. The amount of material excavated for the tunnel was comparatively small. Portals were either hewn out of the natural rock, or often enhanced to appear as if they had been. When the designers called for native stone facings, the specifications were similar to those for culvert headwalls. Tunnels often had the added bonus of viewing galleries that the designers added to relieve the monotony of the dark tunnel, provide for ventilation, and allow the visitor to experience the gradual change in elevation in the road.
Another practice that became standard was roadside cleanup, both following construction and on a regular maintenance basis. John D. Rockefeller, Jr., visited Yellowstone National Park in 1924, and he received a tour personally escorted by then superintendent Albright. Rockefeller viewed conditions along the roadside in Yellowstone in the same way he saw them at Lafayette (Acadia): he wanted to do something about them. At Yellowstone two sets of telephone poles and wires served the concessioner and the National Park Service respectively, and dead and downed timber littered the road edges. Rockefeller saw the need to improve the scenic quality of the park. That fall Rockefeller sent a check for $12,000 to Yellowstone for roadside cleanup. He specified, however, that the money not be used for consolidating the telephone lines on to one set of poles, because he believed the government should be responsible for that. Instead he wanted it used for removal of debris.
The results of the roadside cleanup were so spectacular that Albright prepared a detailed report, complete with photographs, for Rockefeller. The philanthropist was so impressed with what the Park Service was able to accomplish along the road between Norris Geyser Basin and Mammoth Hot Springs that he sent the agency an additional $50,000, which Albright spent over the following four years. The National Park Service pointed to this success at Yellowstone and finally convinced Congress to appropriate funds for moving the phone lines further back in the forest. An additional benefit was that the Park Service included the cost of roadside cleanup in estimates for all new roads. [120]
A final item dogging road development was the question of a centerline. NPS Director Arno Cammerer was concerned about a number of aesthetic issues dealing with park roads, and he stated that he found nothing as disconcerting as the red center stripe on the roads at Yellowstone. He also noted the lack of consistency in colors in the center stripes. Although Yellowstone's was red, Mount Rainier's was yellow, and some other parks had white stripes. He wrote to the head of construction at the Bureau of Public Roads about the inconsistency, and his preference for more rustic stone work along roads. [121]
In November 1935, Cammerer wrote a memorandum to all Superintendents stating that he was convinced that the use of a center line on park roads was not in harmony with NPS policies. He stated that he realized that some exceptions were necessary in light of traffic congestion and safety, but that the park engineer and the park landscape architect should make the recommendation. He reasoned that he wanted to keep the parks "as rustic as possible and avoid doing anything that will give them a sophisticated or city-like appearance.
Cammerer's idea of keeping the roads pristine was not practical, however, in light of the levels of traffic in most park areas. Eventually, all major paved roads in national parks received striping.
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| Fig. 11. In areas of steep, unstable slopes, the Branch of Plans and Design often devised other methods of stabilizing slopes. At Hot Springs National Park, interlocking concrete cribbing stabilized the slope. (National Archives, Record Group 79, Porter Collection, 1936) |
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| Fig. 12. After the slope was stabilized, the specifications called for the erection of a boulder facing, with weathered sides out. (National Archives, Record Group 79, Porter Collection, 1936) |
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| Fig. 13. The slope received soil above the boulder facing and as an in-fill between the weathered stones. The entire slope, including the in-fill, was revegetated. A stone-lined gutter completed the design. On the opposite side of the road a long guardrail edged the downslope. (National Archives, Record Group 79, Port Collection, 1936) |
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| Fig. 14. John D. Rockefeller believed so strongly in the aesthetics of national parks that he funded roadside cleanup projects at several parks, including Lafayette (Acadia) and Yellowstone. This photograph, taken at Yellowstone in 1927, shows how some of the philanthropist's money was spent in removal of downed timber along the road edge. (National Archives, Record Group 79) |
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| Fig. 15. The slopes bordering this culvert at Cades Cove in Great Smoky Mountains National Park received a mulch of local straw to hold native grasses. Cut saplings pegged into the ground stabilized the mat. (National Archives, Record Group 79, n.d.) |
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Last Modified: Mon, Aug 23 2004 10:00:00 pm PDT
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