Listed below are examples of success stories, best practices, and/or innovative tools/approaches. This section will grow as entries are submitted or links to other sites with useful examples are provided. If you believe your agency has utilized a best practice/approach that others could learn from, please submit a short description to AASHTO (including any pertinent links) on the Share Info with AASHTO form. Please note that currently submissions are only being accepted from governmental entities.
A report and set of case studies showcasing transportation agency programs that consider historic preservation in planning and early project development have been issued by the Federal Highway Administration. The report documents 17 case studies organized by program type, including Section 106 programmatic agreements, historic property databases for State DOT rights-of-way, statewide management of historic bridges, and staff liaison programs with State Historic Preservation Offices. The report, which also provides analysis on the effectiveness and benefits of the programs, was prepared in support of FHWA’s Every Day Counts Initiative.
The report contains the following case studies:
For more information, link to the report, Planning And Environmental Linkages For Historic Preservation, and to FHWA’s Planning and Environment Linkages Historic Preservation webpage.
Case studies of best practices for historic bridge rehabilitation from across the country are detailed in a report produced by the Center for Environmental Excellence by AASHTO’s Historic Bridges Community of Practice. The report provides 16 case studies developed in partnership with state DOTs and local transportation agencies and their contractors. For each case study, the report information on each bridge and its context including significant issues associated with project; project description, including purpose and need; traffic levels, loading needs, and other related issues; Section 106 effects finding (no adverse, adverse); and lessons learned.
The report includes the following case studies:
For more information, link to the report, Case Studies on Rehabilitation of Historic Bridges and related resources on the Center for Environmental Excellence by AASHTO website.
The Arizona Department of Transportation (ADOT) has made what it calls an “architecturally challenging” decision to carry out both historic preservation work and transportation safety work in one of the nation’s most significant and infamous towns -- Tombstone.
Tombstone was one of the last frontier boomtowns in the American Old West. In its heyday, it produced millions of dollars of silver bullion and is best known as the site of the Gunfight at the OK Corral. There, ADOT is shoring up water-damaged sections of a local historic landmark called Schieffelin Hall, named for 19th century resident and silver prospector Ed Schieffelin.
Arizona DOT is using adobe bricks to shore up water-damaged sections of a local historic landmark, Schieffelin Hall. Photo: Arizona DOT
“Carrying out preservation work with very unique materials alongside one of our highway projects is not what we do every day,” says ADOT Southeast District Engineer Bill Harmon.
“But in this case, it was a natural fit. We were part of the scope of work for both projects. They both are being carried out in Tombstone’s Historic District. And ADOT is proud to be helping restore and preserve a treasured National Landmark.”
The unique materials Harmon is referring to are adobe bricks. ADOT is shoring up the Hall using replacement bricks that are being painstakingly produced using 19th century techniques. The fabrication process is taking place at a mine not far away in Cochise County by a crew headed up by a third-generation adobe maker. Precise historic replication will enable the new bricks to tightly weld to the remaining original bricks, thus increasing stability and also helping to fend off more water damage.
To create the bricks, wooden molds are set down and a slurry mixture of sand, silt, clay and grass is poured into the forms. After the mixture sits for a day or two and the bricks have taken shape, the forms are removed and the bricks are stacked in the sun to completely dry, a process that can take several weeks. Once the bricks arrive on site at the Hall, they are put into place and secured with a mud and straw mixture that functions like mortar. Finally, a layer of stucco is added on top to conform to the rest of the building’s façade.
|Crews create adobe bricks for restoration of the Schieffelin Hall using historic techniques. Photo: Arizona DOT|
Besides replacing some of the bricks, ADOT also will add a porch to the Hall to replace the original one removed in the early 1900s. Its corrugated metal roof will be supported by wooden posts, and a downspout will be incorporated to carry away rainwater.
Funding for the preservation work comes from a FHWA Transportation Enhancement (TE) grant awarded to the City of Tombstone. The TE grant was the culmination of several years of hard work involving numerous groups including ADOT, the State Historic Preservation Office (SHPO), the Tombstone Restoration Commission, the Federal Highway Administration, and the National Park Service, as well as local government, businesses, and citizens. All work is being carried out according to guidelines from the Department of Interior’s Standards for Rehabilitation, a technique required by the National Historic Preservation Act.
In the same neighborhood as its preservation work, ADOT also is carrying out an associated project to improve motorist and pedestrian safety along the Fremont Street portion of State Route 80 where Schieffelin Hall stands. Funding for the highway safety project comes from FHWA’s Highway Safety Improvement Program under MAP-21 and from state gas-tax dollars.
Key safety features being installed under the ADOT grant, begun in August of this year, include the following:
He continues, “Sadly, part of the impetus for installing extra rigorous safety features came from a tragic crash that took place here in Tombstone in 2009 involving two tourists. After that happened, ADOT and the city of Tombstone began to work together even more closely to implement a range of advanced pedestrian safety improvements.”
In 2010, he says, ADOT and the city of Tombstone completed a comprehensive traffic study soon after the accident. Short-term actions that ensued included road striping, parking restrictions, and reduced speed limits. The study also recommended several longer-term improvements.
Besides the key pedestrian safety features, the project also entails repaving the roadway and constructing new curbs with handicap ramps,, removing an obsolete pedestrian bridge, and installing an irrigation system for landscaping. Driveways not needed by property owners will be closed, others will be improved to meet current standards.
“Construction for both projects is moving forward steadily,” Harmon says. “Our schedule calls for completing both in the spring of 2016. The value of the two projects, combined, is right at $1 million.”
According to Harmon, while it’s not uncommon for ADOT to be involved in the preservation of historic properties through the Transportation Enhancement grants program, it is unusual for the agency to play a role in the preservation of a National Historic Landmark, including such an architecturally challenging project. As he puts it: “This project truly is one of a kind.”
Extensive collaboration took place so that both historic preservation and improved safety goals were met, he continues. The two projects were evaluated together under one NEPA categorical exclusion document. ADOT retained historic preservation specialists to help during the design and construction phases. The restoration concepts were reviewed and approved by the State Historic Preservation Officer. Detailed plans were prepared based on old photographs plus an onsite investigation of the soundness of the walls.
To meet the requirements of both Section 106 of the National Historic Preservation Act (NHPA) and Section 4(f) of the Transportation Act, AZDOT incorporated several historic preservation features. For example, to mitigate the porch’s potential impact on the historic adobe material, the design was tweaked so to have the porch be a free-standing structure rather than be attached. And the street lighting that was installed was carefully chosen in conjunction with the State Historic Preservation Office (SHPO) so as to carry forward aspects of period lighting design.
“Other state DOTs could, and may well be, carrying out similar community improvement projects under what has become the Transportation Alternatives program,” says Harmon.
“But in addition to the challenges of coordination across many different groups, there is also the issue of funding, including matching funds. We were very fortunate in this project to have both the funding and a great group of people who were willing to do what it took to make this happen.”
The project’s most memorable moment to date? Easy one, is Harmon’s reply. It was the day some cattle wandered into the brick-making area and trampled over some of the fresh adobe.
“Not a typical delay at a modern construction site,” he says, “but it probably happened more than once a century or so ago. I guess it’s to be expected when, for historic preservation’s sake, we decide to work on the cutting edge of low technology.”
Archeologists are piecing together a new understanding of residents and merchants who traveled through Delaware as far back as the late 1600s as part of the Delaware Department of Transportation’s US 301 construction project.
The 17-mile, $800 million project will provide a new connection from US Route 301 in Maryland to the existing Delaware State Route 1 corridor.
Spurred on by a tight deadline for construction, archeology work on the project is being conducted at lightning speed and is uncovering numerous archeological sites that are changing the understanding of early inhabitants, merchants, and trade practices in the region, according to David Clarke, an archeologist with DelDOT.
Clarke described the unique $12 million archeology program for the US 301 project, both in terms of the history uncovered at the archaeological sites as well as lessons learned by the state DOT. The large-scale archeological effort was conducted in a short timeframe, while maintaining compliance with requirements of the National Environmental Policy Act and Section 106 of the National Historic Preservation Act.
DelDOT has been able to “front-load” the archeology program with detailed background research and GIS mapping while keeping the project on time and on budget by following a process set forth in a memorandum of agreement among the transportation and resource agencies.
Clarke said the MOA for the project – developed and signed by the Federal Highway Administration, DelDOT, and the Delaware State Historic Preservation Office – is a key element in the “holistic approach” to the Route 301 archaeology program. The program includes a GIS-based predictive model, detailed background research that informed the sampling strategy, and intensive archaeological testing to identify archaeology sites.
“Once we got the record of decision we spent a lot of effort and a lot of money doing very detailed background research and historic research and GIS mapping, so when we had to put shovels in the ground we had so much knowledge already that we weren’t looking for needles in a hay stack,” Clarke said.
In addition, while 99 percent of the archeology work on the project is performed by outside contractors, the program is managed by DelDOT archeologists, giving an added level of confidence to resource agencies and the federal government. “It saves us so much time and money by having archeologists manage the archeologists,” Clarke said.
One of the major accomplishments has been the ability of the program to shift the alignment of the planned highway to avoid archeological resources and preserve sites in-place – a savings of about $5 million and a win-win accomplishment for all involved, he said.
These elements combined have allowed the archeology program to be conducted quicker, cheaper, and more effectively, and to get better results, he added.
“The hope is that at the end of this project this will be a kind of new gold standard both for FHWA and the Delaware Department of Transportation on how to manage the Section 106 compliance on a mega-project,” he said.
Meanwhile, Clarke said archeologists are finding evidence of previously undocumented inhabitants and possible trade routes that may help rewrite the history of the area.
“We have found an amazing number of early historic archeological sites from the late 1600s and throughout the 1700s that we really didn’t expect to be on the landscape and a number of associated cart roads,” Clarke said.
Researchers are finding evidence that merchants likely were using secret trade routes along undocumented cart roads to avoid the more prominent routes that were subject to a tax by the King of England. Trade items from the merchants’ ships – remains of which archeologists are uncovering near the cart roads – were likely used as barter to local farmers and residents who provided access to their land and use of their ox-drawn carts, Clarke explained.
Clarke predicted that these early archeological sites will “completely rewrite and change what we thought we knew about the Delmarva region before the Revolutionary war and at the end of the 1600s and early 1700s – when our previous models told us there weren’t a lot of people living here.”
“We’re finding a lot more evidence of people here and goods trading between the Delaware and Chesapeake Bay – just a lot of it may not have been recorded.”
“Even though we found all of these amazing early archeology sites we are still going to be on-time and on budget, and get through the 106 process, because we set up our program to handle any kind of archeology; no matter what we found we had a way in our memorandum of agreement to work through it.”
Clarke said the new information and data from the U.S. 301 archaeology program will be synthesized and distributed to the public.
In addition to traditional mitigation for project impacts, alternative mitigation will likely include providing a new historic context for the state, journal articles, and possibly an entire book documenting the findings.
Clarke credited the success of the project to the joint effort of the agencies involved.
“We collectively worked very hard to write a memorandum of agreement that allows us the tools to do things differently, but it was also very strict on the roles each agency played, who was in charge, and the decision-making process. Without that legally binding agreement we really couldn’t do the things we’re doing now.”
The Florida Department of Transportation was able to preserve the historically significant architectural features of the Bridge of Lions, the gateway to historic St. Augustine. Accomplished by constructing a “bridge within a bridge,” the improvement project was able to retain key elements of the original bridge while addressing the bridge’s structural problems.
The Bridge of Lions crosses Matanzas Bay (part of the Intracoastal Waterway) and connects the city of St. Augustine with the resort communities of Anastasia Island, St. Johns County, Florida. It is located in an urban setting, with its western approach in the historic district of St. Augustine. Designed by John E. Greiner and constructed in 1927, the bridge has a total length of 1,545 feet. The main span is a 95 foot double-leaf rolling lift bascule. Approach spans are steel arched girder-floor beam spans with cantilevered overhanging sections.
This architectonic bridge is a significant feature of the historic streetscape of St. Augustine and is a gateway to the old city. The bridge was rehabilitated in order to retain its historically significant architectural features, while solving the bridge’s structural problems. This was accomplished by constructing a “bridge within a bridge.” Enough of the old bridge was retained to classify the project as a rehabilitation and not new construction. New construction would have required use of all modern design criteria.
Prior to rehabilitation, the bridge was in fair to poor condition, particularly in terms of the fracture critical girder-floor beam approach spans and the substructure units. At many locations, crutch bents had been previously installed in order to provide additional support.
As part of the rehabilitation, the bridge’s two fascia girders were retained for visual appearance, while new steel stringers were installed inside the girders. The fascia girders, which were removed, repaired, and then reset in place, were relieved of most of the loads and the new stringers now carry the majority of the dead load and the traffic loads. The stringers are hidden from view and will not distract from the architecturally significant arched girders. In addition, the approach spans were widened in order to improve the roadway geometry.
The bascule piers and associated towers were left in place and repaired. This included replacing the existing concrete piers within the splash zone with new concrete, as the existing concrete contained high levels of chlorides. The bascule piers were strengthened by the addition of drilled shafts, and a new footing was placed below the existing waterline footing in order to provide sufficient strength for a modern design scour event.
Several features original to the bridge, but previously removed or replaced, were replicated. These included the pedestrian railing (with the height increased to meet modern standards), light standards, and rotating traffic gates. The bridge steel was painted to match the original bridge color.
The original bridge was recognized as important for its high artistic merit, rather than its technological significance. This made it possible to focus the rehabilitation on its historic character and appearance. This resulted in Florida DOT making a finding of No Adverse Effect. The Florida State Historic Preservation Officer concurred with this finding.
By retaining a sufficient amount of the existing bridge, this project was considered a rehabilitation. New construction would have required use of all modern design criteria, such as widening the navigable channel from the existing 84 foot to the 125 foot width now required for the Intracoastal Waterway.
To maintain the bridge’s historic character, it was extremely important to retain the design of the piers and the arch-shaped fascia beams, in addition to the cantilevered end sections of the girder-floor beam approach spans. The fascia girders were reused on the slightly wider stringer approach spans, supported on substructure units that were rebuilt in-kind to the new geometry. The reused fascia girders support themselves and part of the bridge’s sidewalks.
For more information on the project, contact Roy A. Jackson, State Cultural Resources Coordinator, Florida Department of Transportation, e-mail: email@example.com.
Additional case studies of best practices for historic bridge rehabilitation from across the country are detailed in a report produced by the Center for Environmental Excellence by AASHTO’s Historic Bridges Community of Practice. Link to Case Studies on Rehabilitation of Historic Bridges.
The Pennsylvania Department of Transportation is using an innovative “Story Map” to share important historical information about an area impacted by a road improvement project on Route 322 in Centre County.
The online interactive map provides locations and details about historically significant sites, people, and events within the area of the Potters Mills Gap Transportation Project. Users can learn about the history of the project area and its inhabitants, including the town’s namesake James Potter, Native American settlements, log structures and historic homes inhabited by early settlers, early roads, farms, industry, cemeteries and other features. This effort to document the area’s history is part of an innovative effort to mitigate project impacts on historic resources in the project area.
The road improvement project along a section of Route 322 required mitigation for adverse impacts on several wooded tracts, historic buildings, and historic farmland areas within the Penns/Brush Valley rural historic district. The district was determined eligible for listing in the National Register of Historic Places based on its agricultural patterns, associated landscape features and Vernacular-style architecture established during the nineteenth and twentieth centuries.
The Story Map, titled A Journey to Potters Mills, is the first of its kind to be used by PennDOT to help mitigate adverse impacts to historical resources.
|Screenshot of Journey to Potters Mills Story Map. Courtesy: PennDOT|
“The intent of the Story Map is to provide the public with insight into how the development of transportation within the Potters Mills Gap has, over time, impacted the Historic District,” said Karen Michael, PennDOT District 2 Executive.
According to a PennDOT summary, the Story Map provides visitors with a visual and geographic history of an important crossroads in the Seven Mountains region of the Commonwealth. The map “allows visitors to change scale and navigate between important historic places along the highway corridor and understand the roles that transportation, natural resources, agriculture and early industries played in the development of modern Centre County.”
The Story Map website provides an interactive map of the area with 33 separate image icons that link users to important locations – along with photos, historic maps and documents and a brief description of each. Together, the map allows users to explore the history of the region, from the time of the Native Americans and earliest settlers through various important historic events and locations.
The team sought images which spanned the development of the area, and included diverse subjects and formats including photos, historic maps, portraits, documents, and other records. Information was uncovered through research at a number of repositories, including local historical societies, universities, libraries, state agencies, and from private individuals.
Origins of Story Map Concept
The Story Map concept was proposed to PennDOT by its project consultant as a possible mitigation measure for adverse impacts identified for the project under Section 106 of the National Historic Preservation Act.
“The idea actually came from one of the consultant team members who saw a social media post that combined a map, text and images, but lacked the GIS-based interactivity of what became the Story Map,” according to PennDOT’s Steve Fantechi, who managed the project through preliminary design.
The Story Map was one of a number of mitigation measures that included roadside interpretive signage, context-sensitive design measures, the preparation of a “Best Practices” document, and avoidance and protection of some resources. The NEPA document for the project was an Environmental Assessment that concluded with a Finding of No Significant Impact.
According to Fantechi, the Section 106 consultation process involved a great deal of consultation and interaction with local historical societies and local governments. “That collaboration contributed substantially to Story Map’s popularity with local residents, the regional press, teachers, and citizens and engendered a substantial amount of local and regional pride in local heritage,” he said. “In our view that’s what a successful Section 106 outcome looks like.”
In addition, he said, the GIS-based Story Map approach also creates an obvious link between landscape, transportation networks, and economic history, which in turn promotes a better understanding of and context for historic events, trends and places.
To the best of PennDOT’s knowledge, this is the first mitigation product of its type used for an American transportation project.
Challenges and Lessons Learned
According to PennDOT District 2 staff, the biggest challenge in developing the Story Map was probably too much of a good thing.
Background research and interaction with the consulting parties produced an enormous number of images and a substantial amount of local history and documents. Paring that down to a relevant and manageable record of local and regional history was a challenge.
Once that work was done, the actual GIS programming required to produce an interactive and useable online product had its own set of challenges, as the product went through a number of iterations leading to the final version.
Another challenge came from requests by some of the consulting partners to add additional information to the Story Map for future projects. Since PennDOT used a consultant to develop the Story Map, its ability to revise the map was limited to the duration and funding of the consultant’s contract. PennDOT doesn’t have the resources to revise the Story Map in-house, so future revisions, which could involve different consultants, could be more difficult, according to PennDOT Project Manager Craig Sattesahn.
Regarding lessons learned, Sattesahn said it would have been useful to establish procedures and parameters up front to facilitate revisions and additional requests.
Advice for Other DOTs
According to PennDOT staff, close and meaningful consultation with local consulting parties and residents is key to local support for the product and can help obtain a great deal of important local input – such as family images, diaries, etc. – that would be impossible to get anywhere else.
It’s also important to balance high-tech and low-tech mitigation measures. Older residents are less technologically savvy than younger ones, and there are still many remote locations where high speed internet conductivity is spotty.
Since the Story Map is a technology-based product, the rapid change and evolution of technology requires attention. Although no funding is available to carry the Potters Mills Gap Story Map further, it’s likely that the next iteration of a Story Map on a different project would probably be a mobile application.
As a final consideration, PennDOT staff said a central online state repository for Story Maps from multiple projects is probably worthwhile and would not be a very expensive effort. Such a site would allow visitors to start a search at the state map level and zoom in to a number of specific project areas that have Story Maps.
The first of three construction sections of the Potters Mills Gap Transportation Project was completed in 2015. A second section began construction in August 2016, and the last section is scheduled to start construction in early 2018. More information about the PMG Transportation Project is available on the project web page.
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