Photo by JMS Visual Communications
As related to transportation services, the term sustainability has a variety of meanings and is relevant to both highway and bridge design and construction. Regardless, the integration of sustainable features is very much client-driven. In fact, more and more public and private transportation clients are requiring a sustainable approach because it is the right thing to do.
During the past 20 years, transportation design has changed dramatically in the U.S., and designers and builders are now more sensitive to projects’ potential impact on the environment and communities. New and improved design and construction methods have evolved following the completion of the Interstate Highway System. Interestingly, today, roads and bridges are to have a 100-year design life.
Photo by Robert Meier
Gannett Fleming has been at the forefront of this changing industry and a leader in implementing a context-sensitive solutions (CSS) design approach. This is a collaborative, interdisciplinary approach that involves all stakeholders to develop a transportation facility that fits its physical setting and preserves scenic, aesthetic, historic, and environmental resources, while maintaining safety and mobility. Environmental stewardship and preservation are key components of CSS. Ensuring this requires a variety of sustainable features and techniques.
Sustainable Features & Techniques
- Addressing congestion, which misuses peoples’ time and fuel, as well as creates pollution, is being addressed with new traffic controls, such as round-a-bouts rather than traditional stop lights.
- LED roadway lighting and traffic signals, which last approximately 10 times longer and are much brighter than traditional lighting, are being used more and more.
- If inevitable environmental impacts are made, such techniques as re-vegetation and new tree plantings are implemented.
- A significant amount of materials used on highways and bridges are now made of recycled content, including asphalt, cement, and steel. Today, green steel bridges are built using more than 50 percent recycled steel. Also, green concrete bridges are built with cement substitutes, or recycled materials from other industries, which also adds increased strength and durability. In both instances, carbon dioxide emissions are greatly reduced.
- Today, many bridge projects involve rehabilitating an existing structure rather than building a new one through the increased use of new materials and updated procedures. Many bridge components are reused rather than replaced.
- Watershed-based stormwater management and stream restorations are components of the green highways solutions utilized to mitigate roadway impacts.
19th Avenue over Grand Canal Bridge Retrofit
Client: City of Phoenix
Location: Phoenix, Arizona
The 19th Avenue Bridge is the first
smart structure in the City of
The 19th Avenue over Grand Canal Bridge, a three-span continuous concrete slab bridge originally constructed in 1946 and widened in the 1960s, carries an average daily traffic of 30,000 vehicles. Similar to many bridges of that era, the 19th Avenue Bridge had reached the end of its service life due to increased traffic volumes and deterioration, resulting in the need for rehabilitation or total replacement.
A fast-paced approach to rehabilitation and improving the load carrying capacity of the existing structure was required. Several alternatives were considered, including a total structure replacement that would have cost approximately $4 million and likely caused traffic congestion and delays.
The project team used a concept that would not only reduce adverse effects on the environment typically associated with new construction activities, but also one that would not cause traffic delay. The concept involved using advanced technology and Fiber Reinforced Polymer (FRP) composite materials. This sustainable approach greatly reduced costs while achieving the required load carrying capacities. In addition to the speed and ease of installation, the estimated cost of the FRP rehabilitation construction was approximately $700,000, resulting in a savings of $3.3 million to the city.
CFRP rebars were embedded in
the concrete over the pier at the
negative moment regions
FRP composite materials possess superior characteristics when compared to traditional bridge building materials. These characteristics include high tensile strength and modulus; high resistance to fatigue and corrosion; effortless fabrication, shipping, and jobsite handling; and easy and speedy installation. The externally applied FRP system selected to strengthen the bridge consisted of Carbon Fiber Reinforced Polymer (CFRP) wraps, or fabric installed on the soffit of the bridge and CFRP rebars embedded in the concrete over the piers.
This project received a Grand Award (Small Projects category; Transportation – Bridges) in the American Council of Engineering Companies of Arizona’s 2008 Engineering Excellence Awards.
- The team completed this project with limited disturbance to the canal in three weeks, as compared to a total bridge replacement estimated at 11 months
- The team preserved the existing investment and saved construction materials that would have been required for complete replacement
- The bridge is the first smart structure in the City of Phoenix, and the first of its kind in the state of Arizona; it was instrumented with a continuous, real-time monitoring system that is powered with a solar array, and data is uploaded wirelessly to a Web site that is easily accessed by the city
- Completing the project within the three-week dry period preserved the natural flow of the canal, and the quick installation resulted in less disruption to the environment in the forms of air and noise pollution
- By rehabilitating the bridge, the team salvaged and recycled the original structure
The superior results achieved through the use of the sustainable FRP composite materials will enable the city to upgrade similar bridges and structures with low or poor ratings with significant cost savings. To date, two additional bridges have been upgraded using the FRP approach, and an estimated 13 additional bridges are currently in need of an upgrade. The total savings for the city by utilizing FRP composites could reach $60 million.
Route 18 Extension
Client: New Jersey Department of Transportation (NJDOT)
Location: Piscataway Township, Middlesex County, New Jersey
Bridge piers incorporated drilled
shafts to span Metlars Brook and
reduce construction impacts
The $90 million Route 18 Extension project is a 2.1-mile-long highway segment with three interchanges that provides the connectivity to Interstate 287 and access to Rutgers, The State University, and the Piscataway Township Business Center. This vital route carries more than 40,000 vehicles every day.
The project limits encompass the Raritan Landing Archaeological District, revolutionary war encampments, and two national register historic buildings. As a result, the required $5.8 million Raritan Landing Data Recovery constituted the largest single archaeological data recovery undertaking sponsored by the NJDOT. In addition, a multitude of sensitive natural resources and parklands were within the project limits, and the project team was committed to environmental stewardship.
Photo by JMS Visual Communications
The project’s reforestation plan
replanted 5,000 trees within the
project limits, and 5,000 additional
trees throughout the community
This project received a 2005 American Road & Transportation Builders Association (ARTBA) GLOBE Award in the Major Highways/$10-100 million Category. This award recognizes excellence in environmental protection and mitigation within the transportation industry.
- Accelerated schedule, large-scale excavations were conducted at the Archaeological District in advance of the construction contract
- Complex interchange and roadway alignments of this project “thread the needle” to balance impacts of competing environmental resources
- A re-forestation plan was implemented to mitigate encroachment into the Rutgers Ecological Preserve, and thousands of plantings were incorporated into the project on- and off-site
- Freshwater wetland mitigation was established on site, the Raritan Floodway was re-delineated, and the River Road Interchange configured to avoid impacts to the floodway and floodplain
- The Metlars Brook was realigned and culverting minimized; locations of culverts were oversized open-graded bottom arch culverts to maintain a natural stream bed and allow flood storage
- Stream banks were re-vegetated with wetland plantings with grading set to allow re-creation of pools and riffles
- Numerous innovative environmental mitigation techniques were incorporated
- Additional bridge spans
- The use of extensive retaining walls were implemented across the floodplain
- Drilled shaft foundations carry bridge piers to minimize the footprint impacts
- Retaining walls were incorporated to minimize embankment, wetland encroachment, and impact to historic properties
- Water quality was obtained through best management practices of basins and mechanical treatment devices, the first accepted by the NJDEP
- Stormwater clarifiers were utilized to remove contaminated sediment and debris from surface runoff before discharging into the Raritan River
- Work restrictions in environmentally sensitive areas and soil erosion and sediment control were mandated in the contract documents
- A construction moratorium was observed during the fish spawning and deer rut season to minimize the impact on wildlife
Route 30 Transportation Improvement Project
Client: Pennsylvania Department of Transportation (PennDOT)
Location: Bedford and Snake Spring Townships in Bedford County, Pennsylvania
Photo by Robert Meier Architectural
Preserved historic Hartley Pond
and nearby spring house
The primary goal of this 4.7-mile, $67.7 million project was relieving traffic congestion along the corridor. The average daily traffic (ADT) projected for the year 2025 is 39,900.
A five-lane facility replaced the pre-project roadway, which was comprised of two- and three-lane sections. Several structures were reconstructed, and a new parallel bridge across the Juniata River was built. In addition, the Pennsylvania Turnpike Bridge over Route 30 was replaced, and 1.2 miles of approach roadway work was completed. Also, the bridge that carries Route 30 over Snake Spring Valley Run was replaced, and two mechanically stabilized earth retaining walls were constructed in order to preserve various historic properties.
Photo by Robert Meier Architectural
The project team re-vegetated the
riverbanks of the Juniata River
Avoidance, minimization, and compensation of impacts are all significant components of environmental mitigation. PennDOT applied these techniques to ensure this project’s success and exceed both the public and regulatory agencies’ expectations. This project received a 2007 American Road & Transportation Builders Association (ARTBA) GLOBE Award, which recognizes excellence in environmental protection and mitigation within the transportation industry.
- The project’s existing arch bridge was reconstructed in order to preserve this historic structure; this also resulted in significant cost savings
- The construction schedule avoided impacts to the Indiana bat population and the protected animal’s habitat
- The riverbanks were re-vegetated with a wetland seed mix and trees that match those lost where disturbance occurred during construction of the causeway access roads
- The project incorporated the repair and stabilization of a small stream
- The riparian and floodplain habitats along the Raystown Branch at Rivercrest were restored and included the removal of all above-ground buildings, the re-vegetation of the disturbed areas with native vegetation, and the installation of duck nesting structures and bat boxes
- A survey of the brook floater, which is a species of freshwater mussel that is thought to reside in the Raystown Branch, was conducted, even though not required to achieve regulatory compliance
- PennDOT designed temporary causeways in the Raystown Branch to avoid unexpected impacts on additional aquatic species
- Historic Hartley Pond and the nearby spring house were preserved
Transportation Management Plan – Andrews and Bolling Air Force Bases
Client: Military Surface Deployment and Distribution Command, Transportation Engineering Agency (SDDCTEA)
Location: Metro Washington, D.C.
Bolling Air Force Base
SDDCTEA tasked Gannett Fleming to conduct a Transportation Management Plan (TMP) for Andrews and Bolling Air Force Bases. The purpose of this TMP was to assess vehicular and pedestrian travel, parking conditions, and transit services, as well as identify transportation needs for the future addition of personnel.
The TMP includes analysis of travel modes, trip timing, frequency and length, and travel routes. It was used to identify or validate alternate transportation needs and initiate an active plan to promote more efficient employee commuting patterns. The goal of the TMP is to reduce vehicular travel to the bases by encouraging alternative modes of transportation.
Andrews Air Force Base
The project team developed a traffic model to estimate the decrease in delay, fuel, and emissions with various levels of vehicular travel reductions. It then outlined its multimodal recommendations, which aided the district in its base access planning efforts with state and local government entities.
The TMP was conducted in accordance with the National Capital Planning Commission Comprehensive Plan and the Federal Transportation Management Program Handbook. As a token of its appreciation for Gannett Fleming on this project, the Air Force District of Washington presented our firm with its organizational coin.
Goals of TMP:
- Outline steps to reduce single-occupant vehicle commuting
- Encourage reduction in vehicular trips through policies that:
- Support bicycle commuting
- Reward ridesharing
- Bolster transit use by encouraging new transit services and enhanced pedestrian environments
- Support alternate meeting/work venues, such as video teleconferencing and telecommuting
- Improve efficiency of vehicle movement entering, exiting, and within the base
New Jersey Turnpike Widening Project, Reconfiguration of Interchange 8
Client: New Jersey Turnpike
Location: East Windsor Township, Mercer County, N.J.
As part of a $2.5 billion project for the New Jersey Turnpike, Gannett Fleming is designing two key sections of the roadway. The goal of this overall major widening project is to widen the existing six-lane dual roadway to a 12-lane dual-dual roadway.
Gannett Fleming designed approximately 35 percent of the reconfiguration of Interchange 8, which stretches from milepost 66.8 to milepost 68.3. This 1.5-mile section includes 13 structures requiring construction, modification, or replacement, as well as a new toll plaza. The most significant roadway aspect of Gannett Fleming’s efforts involves the Turnpike’s first single-point urban interchange at Routes 33 and 133.
Interestingly, Gannett Fleming was selected for this assignment not only because of its vast roadway and bridge design capabilities, but also because of its in-depth knowledge and experience in toll facility design and sustainable design expertise. The toll plaza and associated administration building is registered with the certification goal of LEED® Silver. The design for this project was completed in early 2010, and groundbreaking took place in August 2010. Construction is anticipated to be complete by the end of 2011.
Toll Plaza’s Sustainable Features:
- Will be the Turnpike’s first LEED project, as well as the first LEED toll plaza in the U.S.
- Overall, it will use 15 percent less energy and 40 percent less potable water annually when compared to a typical administration facility. Some of the notable design features include:
- Low-flush and low-flow fixtures
- Locally sourced materials
- Efficient fluorescent lighting
- Recycled content in building materials
- Indigenous landscape that will not require irrigation or maintenance
- Natural daylighting and occupancy sensors: non-VOC paints, coatings finishes, and products
- Rapidly renewable materials, such as bamboo
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