Featuring developments in Federal highway policies, programs, and research and technology.
|This magazine is an archived publication and may contain dated technical, contact, and link information.|
|Federal Highway Administration > Publications > Public Roads > Vol. 70 · No. 3 > Saving a National Treasure|
Publication Number: FHWA-HRT-2006-001
Saving a National Treasure
by Amy Vanderbilt and Steve Moler
FHWA and the National Park Service embark on a monumental restoration of Montana's historic Going-to-the-Sun Road.
The Going-to-the-Sun Road in Montana's Glacier National Park was once described as "the most beautiful piece of mountain road in the world." Those words, spoken by park Superintendent Eivind Scoyen to several thousand spectators at the road's 1933 dedication ceremony, will continue to ring true for many users now that a historic rehabilitation is underway.
The Sun Road, as some abbreviate it, is an 80.5-kilometer (50-mile), two-lane highway that winds through the heart of the park, up the steep slopes of the Continental Divide, and over 2,026-meter (6,646-foot) Logan Pass. Motorists can experience what some view as the most spectacular mountain scenery in North America -- glacier-carved peaks, deep blue lakes, and lush forests.
The highway itself, built mostly between 1921 and 1937, is considered an engineering marvel by virtue of its designation as a National Civil Engineering Landmark. Most of the 19-kilometer (12-mile) "alpine," or high mountain, section over Logan Pass was built into the sides of near-vertical cliffs using a network of stonemasonry bridges, tunnels, and arches. A series of 130 retaining walls support the roadbed along the steepest sections, and more than 11 kilometers (7 miles) of guard walls and guardrails help guide motorists and keep them on the road. These stonemasonry guard walls give the road much of its historic character and architectural aesthetic appeal.
Today the Sun Road has more than 475,000 vehicles traveling it during Glacier's peak visitor season from June to October, or about 3,500 vehicles per day. Approximately 80 percent of the park's two million annual visitors travel the road, according to park surveys.
However, 70 years of rockslides and avalanches, severe weather, heavy traffic, and inadequate maintenance left the road in urgent need of repair. Without aggressive action, the historic structures for which the Sun Road is so admired might have been lost forever.
Preserving a National Treasure
The National Park Service (NPS) and Federal Highway Administration (FHWA) have embarked on a monumental rehabilitation project to save this national treasure. Indeed, the most urgent repairs on structures in danger of catastrophic failure were completed during previous phases. The two agencies originally intended to invest $140 million to $170 million over 7 to 8 years to restore the Sun Road's entire length. However, due to a lack of available funding,complete restoration could take 10 to 20 years. As a result, both agencies in partnership with local, State, and Federal officials are committed to completing the Sun Road rehabilitation under the earliest possible timetable, as funding allows. The effort involves repairing damaged and deteriorating stonemasonry retaining walls and guard walls, inadequate drainage systems, crumbling pavement, and tunnels and bridges. Safety improvements will be made at high-priority rockfall locations and at pullouts, overlooks, and parking areas. A comprehensive mitigation program will limit impacts on tourism.
"This is the largest and most complex project our office has ever undertaken," says Ricardo Suarez, project delivery director and acting division engineer for FHWA's Western Federal Lands Highway Division (WFLHD), which is jointly managing the project with NPS.
The project is also one of the largest road rehabilitations in NPS history, according to Glacier Superintendent Mick Holm. "The road is not the only jewel in the park's 'crown,' but a trip across the Sun Road does provide an iconic experience for a vast number of Glacier's visitors," he says. "The scope and magnitude of this project is clearly unprecedented and daunting. But I believe we can and must do nothing short of completing this rehabilitation in a timely manner, thereby preserving this phenomenal mountain byway experience for generations to come."
A Monumental Task
The Sun Road rehabilitation actually began in the late 1980s at the village and park entry point of West Glacier. The remaining work involves about 13 construction phases in all. The first four, to rehabilitate the most severely damaged retaining walls, have already been completed through Park Roads and Parkways funding, a joint NPS-FHWA program to develop and maintain roadways throughout the national park system. Phase 5 was completed in 2005 and involved rehabilitating the West Side Tunnel's east portal and high-priority guard walls, correcting various drainage and roadside deficiencies, and repairing damage from a recent rockslide.
But it is the remaining phases that have turned the Sun Road work into an extraordinary project. Those phases involve rehabilitating the entire roadway itself and making the most critical and complex repairs to historic structures along the alpine section. Under a more typical schedule, this work would have been completed in small segments over a much longer period, but for economic and environmental reasons, NPS and WFLHD have decided to accelerate construction so the final phases can be completed more rapidly than past repairs.
The final phases were assessed under an environmental impact statement (EIS) and two records of decision (RODs), one by the NPS and the other by WFLHD. All the work will be done while the road remains open during the normal tourist season. The RODs were based on an accelerated rehabilitation schedule and were dependent on projections of increased project funding from the Park Roads and Parkways program; a congressional earmark from the new transportation reauthorization bill, the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users; and other sources.
"I compare the Sun Road rehab to the restoration of the Statue of Liberty in the mid-1980s," says Ron Carmichael, former WFLHD division engineer who worked on the project during most of its early planning until retiring in September 2005. "Like the statue, the Sun Road is a national treasure that has fallen into disrepair. It is our obligation to rehab the road in a way that replicates the intent of the original constructors while preserving the historic and cultural resources and the visitor experience that was originally intended."
Many Challenges Ahead
Construction on the remaining phases is expected to be complex and challenging, according to engineering studies. Work can be done only 5 to 6 months of the year, typically mid-May to mid-October, because of harsh weather and the annual winter road closure. The terrain where much of the work will be performed is steep, and the roadway is extremely narrow, less than 6 meters (20 feet) wide along many stretches. Adding to the difficulties is the requirement that the road remain open throughout the entire rehabilitation. Finally, its designation as a National Historic Landmark requires NPS and WFLHD to minimize harm to the road's historic character and fabric in accordance with the Secretary of Interior's Standards for the Treatment of Historic Properties and related Federal and State regulations.
Rehabilitation will focus on five high-priority engineering areas:
Retaining walls, arches, and tunnels. Many of the road's stonemasonry retaining walls suffer from structural deterioration, primarily from age and impacts from rockslides, vehicles, and avalanches. Damage also has been caused by rain and snowmelt repeatedly freezing and thawing inside and behind the walls. Thirteen retaining walls, determined by WFLHD to be in immediate danger of catastrophic failure, were repaired in the first four phases. Remaining problems include decaying and inadequate foundations, poor embankment stability, inadequate drainage, and the breakdown of mortar (the binding that holds the stones together).
To solve these problems, many sections of retaining walls either have been or will be "repointed" with new mortar. In more severe cases entire walls will be rebuilt. Some retaining walls will be preserved by building second, hidden walls behind them to carry some of the structural load.
Guard walls and removable guardrails. Many sections of the road's stonemasonry guard walls have suffered damage from age, impacts from vehicles, avalanches, and rockslides, and improper repairs over several decades. As with the retaining walls, water seepage has caused cement on some guard walls to leach out from the grout. Some guard walls have just a few stones broken or missing, while parts of others have been sheared off or are leaning precariously over cliffs.
Entire sections of guard wall will have to be completely reconstructed in the most severe cases. In others, missing stones can simply be replaced. To meet current safety standards for guard wall height, either the walls will be raised or the road grade lowered.
For decades, finding a reliable and high-quality supply of historically compatible stone has been a challenge. Having assessed surrounding quarries, WFLHD and NPS currently are evaluating three possible sites with the required stone—Helena Formation limestone—with a preferred site expected to be chosen soon.
The Sun Road has 70 documented avalanche chutes where stonemasonry guard walls are susceptible to damage. Over the years NPS has installed various types of removable timber guardrails so avalanches pass over the road without causing damage. However, the original log rails of the 1930s were not crashworthy in that they did not withstand vehicles hitting them and over time were found to crowd travel lanes as larger vehicles began using the road. Also, the high maintenance costs of removing the rails in the fall and reinstalling them each spring prompted NPS and WFLHD to seek other options.
Recent projects have used a new generation of removable guardrails that have been crash-tested and designed to protrude no farther into the travel lane than the guard walls. The new rails are more historically authentic and aesthetically pleasing to many than their predecessors.
New avalanche-resistant guard walls have been constructed with a reinforced concrete foundation and core, then finished with a historically compatible stonemasonry facing. A concrete slab anchored with small piles (micropiles) was laid within the roadway underneath the new guard wall, and the concrete colored to match the adjacent asphalt pavement. Two prototype guard walls performed well in a winter 2004 demonstration project, according to former WFLHD Project Manager Dick Gatten, who retired in January 2006. Each avalanche site, he says, will be evaluated to determine whether a resistant guard wall or removable guardrail will be installed.
Drainage. Many of the road's original drainage systems are still functioning as designed, but some added after the road was paved in the 1950s now suffer a variety of problems, from broken and separated pipes to crumbling stonemasonry headwalls. All historic structures slated for repair or rehabilitation will be designed with new drainage features to minimize water seepage and other damage due to the harsh climate. Structures not needing repair will have their drainage systems evaluated and rebuilt if necessary, with enlarged culverts.
Slope stability. Rockfall safety hazards are present along the steepest road sections because of unstable slopes and rock cuts, according to engineering studies. The roadway is also "creeping" (shifting) because of drainage problems, fill settlement, and avalanches.
Removing rockfall hazards within the original cut will involve selective rock scaling, the process of removing potentially loose and unstable slabs and outcrops before they crash down on the roadway. Those that are too large to scale will be bolted or anchored to more stable rock foundations. Also, to help support unstable rock, holes are drilled below the rocks that are to be stabilized; steel dowels are inserted; "shotcrete," a type of concrete, is applied under pressure between the rocks and dowels; then the shotcrete is shaped, textured, and colored to match its surroundings. Slumping or creeping roadways will be evaluated and, if necessary, corrected with drainage improvements, retaining wall construction, reinforced earth, tieback anchors, and micropiles.
Pavement. The roadway in many locations has deficient subgrade and road base, and along many other sections the surface is damaged and uneven. Solutions involve subexcavation to remove and replace unsuitable subgrade and road base material, as well as laying new pavement. Damaged or uneven pavement will be repaired and repaved. Remaining sections will be resurfaced.
Success Starts With Careful Planning
A project of this magnitude requires years of intense and collaborative planning. The process for completing the final phases on a faster-than normal schedule began in the mid-1990s, when NPS and WFLHD launched a retaining wall management program to identify, evaluate, and monitor the Sun Road's 130 retaining walls. Having found serious structural problems in many of the walls, the agencies collaborated on various studies and initiatives in the late 1990s and early 2000s that led to the decision to rehabilitate the entire road—and as quickly as possible to prevent catastrophic wall failures and minimize impacts on the park and its visitors.
One initiative during the planning process involved forming a congressionally authorized Citizens Advisory Committee in February 2000 to help NPS develop initial alternatives that were considered in the project's EIS. In addition to potential environmental and social impacts, the committee had to consider other issues, including project costs, scheduling, and historic preservation.
A major goal of the rehabilitation is maintaining the quality of the visitor experience, particularly during construction. Glacier is a world-famous destination that accounts for much of the region's tourism. A sudden dramatic drop in visitation because of intense construction along its most popular sightseeing route could result in undesirable economic consequences. The committee spent about a year and a half developing five recommended alternatives. All but one of the alternatives were analyzed in the project EIS as follows.
Alternative 1: Repair as Needed or No Action. Under this option, rehabilitation would continue as funding allowed over 50 years at an annual cost of $7 million to $8 million. Work would primarily focus on critical and emergency repairs without substantial long-range planning. This alternative was rejected because the badly needed repairs would not occur soon enough to preserve and protect the features and character of the Sun Road as a National Historic Landmark.
Alternative 2: Priority Rehabilitation. Rehabilitation would occur over 20 years, with total funding at $157 million to $186 million, or about $8 million to $9 million per year. The road would remain open to visitors, and a maximum cumulative delay of 30 minutes would be allowed when traveling the Sun Road's entire length. This option would allow for advance planning to rehabilitate high-priority sites and would address current structural road deficiencies but with only a few improvements to visitor facilities, such as turnouts, parking areas, and walkway access to interpretive sites. This option was not selected because repairs would not occur soon enough, resulting in continued road deterioration, loss of historic features, possible damage to natural resources, and greater economic impacts than Alternative 3.
Alternative 3: Shared Use With Extended Rehabilitation Season. Rehabilitation would occur over 7 to 8 years at a total cost of $140 million to $170 million, or about $18 million to $24 million per year, provided the needed funding would be available or unforeseen delays did not occur. This alternative would accomplish the needed road repairs while maintaining visitor use and access to the Sun Road. Roadwork would be conducted throughout the visitor season, but work requiring substantial traffic delays would occur during the shoulder season, the time prior to mid-June and after mid-September. Otherwise, a maximum cumulative delay of 30 minutes would be allowed when traveling over the length of the road between mid-June and mid-September, the peak season. Up to 1 hour of cumulative delays over the length of the road would be possible during nonpeak hours in the mornings (8 a.m. to 10 a.m.) and evenings (3 p.m. to 8 p.m.), Monday through Thursday. Variable traffic delays would be used for night work, with advance notice to the public of the construction schedule.
Alternative 4: Accelerated Completion With Isolated Road Segment Traffic Suspensions. The objective of this alternative would be to complete the rehabilitation as soon as possible by using isolated traffic suspensions Monday through Thursday from the months of May through October. Visitor access would be maintained on the weekends. This alternative planned for repairs to be completed in 6 to 8 years at a cost of $126 million to $144 million, or $16 million to $24 million per year. Alternative 4 contained the same visitor use improvements and visitor development mitigation funding as Alter-native 3. Because of the faster rate of repair, Alternative 4 would have minimized further deterioration to the Sun Road and historic, cultural, and natural resources. However, it would have the greatest impact on park visitation and annual impact on the local economy. Therefore, Alternative 4 was rejected.
Preferred Alternative—Open for Business
During the EIS process, which included extensive public involvement through meetings, open houses, and a 60-day comment period, NPS and WFLHD selected Alternative 3 (Shared Use) as the best option. After some small changes, Shared Use was documented and approved in the NPS's ROD in November 2003 and WFLHD's ROD in March 2004 because it provided the best balance of protecting historic, scenic, and natural resources while minimizing economic impacts.
Since the final EIS and documentation in the RODs, the anticipated funding levels required to complete the entire repairs in 7 to 8 years did not become available. Consequently, NPS and WFLHD are jointly developing a strategy that will include public involvement and repair of the Sun Road in the earliest possible timetable, as available funding allows.
Keeping Business as Usual
These strict road-closure limitations and the need to reduce traffic congestion became the driving force behind development of a comprehensive mitigation program. How to keep 3,500 vehicles moving through a major construction zone every day on a narrow, steep mountain road without causing gridlock was one of the biggest challenges from the outset, according to Superintendent Holm. "During the next decade, visitors driving over the Sun Road are going to see more construction than normal," he says. "So we needed to take measures to mitigate this. We want to make the driving experience as enjoyable and trouble free as possible."
One of the first efforts toward this goal was completion of a construction sequencing strategy that details when and how all pieces of the rehabilitation puzzle will fit together to minimize traffic congestion and delays. The strategy calls for construction to progress generally from west to east where traffic will be reduced to one lane most of the time. Temporary traffic signals, vehicle-actuated devices set on fixed cycles for times other than the actual work period, will be installed at each end of most work zones to control one-way traffic. During the work periods, flaggers usually will work in two-person teams, one to control traffic and the other to walk the lines of stopped vehicles to answer questions and provide information.
WFLHD is using a traffic modeling computer program called QuickZone to predict traffic impacts at each work zone. The program can estimate traffic backups, delay times, and optimum construction schedules, and can estimate impacts resulting from construction schedule changes, flaggers, and signal timing.
Leave the Driving to Glacier
Another key component of the mitigation program is a new voluntary transit system. Visitors will still be able to drive their own vehicles over the road as usual, but they will have the option of leaving their cars at two transit centers—one at each end of the park—and taking regularly scheduled shuttle buses to the Sun Road's most popular destinations, such as trailheads, overlooks, and interpretive sites. The system will be phased in over two seasons, with initial service covering a limited area starting in summer 2007 and the whole system scheduled to be fully implemented over the entire Sun Road by summer 2008. The transit center near the west entrance will be a new facility featuring a building where riders can obtain transit and road project information, a sheltered pickup and dropoff area for riders of the shuttle buses, and parking for about 150 vehicles.
A Federal, State, and local partnership has been established to purchase and operate the shuttle bus fleet during both the construction and off-seasons. The off-season program will help meet other Montana-wide transit needs and make the entire transit system more cost effective. This partnership with the Montana Department of Transportation will leverage existing Flathead and Glacier County maintenance facilities, provide year-round employment in local gateway communities, and reduce the direct burden on FHWA and NPS for operating and maintaining the system.
"We are really encouraging our visitors to use the transit system whenever possible, once it's up and running," says Superintendent Holm. "Our goal is to reduce vehicle traffic on the Sun Road by 10 percent. If we can reach this goal, I think the driving experience will be enjoyable for everyone, whether you decide to drive, take an interpretive tour with either Sun Tours or aboard the historic red buses, or take a shuttle bus."
Smart Transportation System
The entire Sun Road mitigation program will be supported by an extensive intelligent transportation system (ITS) computerized communications network that will provide real-time information to visitors regarding road conditions, parking availability, traffic, weather, transit schedules, and more. For example, travelers planning a trip to Glacier, or en route to the park, will be able to receive construction information via the Internet, highway advisory radio, Montana's 511 telephone traffic information system, and variable message signs strategically located inside and near the park.
Other features to enhance the visitor experience include new interpretive signs and exhibits at transit stops and other strategic locations that tell the story of the park's history, wildlife, plant life, and the construction of the original Sun Road. Several locations will have interactive information kiosks.
In addition to ITS technologies and enhanced educational services, the mitigation program will mount a comprehensive public information effort, identified by the advisory committee as an essential element in the Sun Road rehabilitation. This initiative will provide timely and accurate information through a variety of sources, such as the Internet, travel and tourism guides and magazines, the news media, brochures and signs at surrounding communities, gateway tourism and travel businesses, and public service announcements. The public information and outreach also will include customer service training for frontline employees about the project and related services.
The extraordinary effort that NPS and WFLHD are making to maximize the Glacier National Park experience throughout the entire construction project gives visitors added opportunities to witness history in the making -- the preservation of a national treasure.
Amy Vanderbilt is the public affairs and outreach manager at Glacier National Park. She has been with NPS for 25 years, primarily in public affairs and incident information positions at Glacier, Grand Teton, Yellowstone, and Yosemite national parks. She also served as a lead information officer for the NPS all-risk incident management team from 1995 to 1998. She can be reached at 406-888-7906 or email@example.com.
Steve Moler is a public affairs specialist at FHWA's Resource Center in San Francisco. He has been with FHWA for 6 years, providing the agency's field offices and partners with support in media relations, public relations, and public involvement communications. He can be reached at 415-744-3103 or firstname.lastname@example.org.
The authors would like to thank Jack Gordon, Glacier's landscape architect, for his substantial contribution to this article. For more information on the Going-to-the-Sun Road rehabilitation and road status, go to http://www.nps.gov/archive/glac/sunroad/whatsup.htm or http://www.nps.gov/archive/glac/montana.htm. The 511 Traveler Information and QuickZone are two of the FHWA priority, market-ready technologies, which are innovations that have proven benefits and are ready for deployment (see www.fhwa.dot.gov/crt/lifecycle/ptisafety.cfm).
Page Owner: Office of Corporate Research, Technology, and Innovation Management
Scheduled Update: Archive - No Update
Technical Issues: TFHRC.WebMaster@dot.gov