Backhoe on a bridge installing concrete culvert.

Incorporating ‘Green Infrastructure’ into Transportation Projects: Part 2

The National Cooperative Highway Research Program (NCHRP) released a report in February 2021 highlighting several state agency efforts to incorporate Green Infrastructure (GI) solutions into transportation drainage and landscaping design. 

The American Association of State Highway and Transportation Officials helped research and publish that report – entitled Landscape Design Practices for Roadside Water Management: Domestic Scan 16-02 – as part of the joint AASHTO and Federal Highway Administration’s NCHRP “Domestic Scan Program.” That program helps speed up the transfer of information and technology among transportation agencies. 

This article is the second of a two-part series – focusing on GI recommendations for state transportation agencies.

How and where can state departments of transportation incorporate Green Infrastructure or “GI” practices into their ongoing infrastructure programs? A four-day workshop organized by the team that crafted the Landscape Design Practices for Roadside Water Management: Domestic Scan 16-02 report came up with eight recommendations that can help build a successful GI program with long-term results, across varied climates, geographies, and topographies.

[Above photo by Colorado DOT]

The first is to define what GI is, as the workshop participants discerned at the outset that there is no nationally recognized standard GI definition – and an agreed-upon definition is needed to support grant funding consistency, federal eligibility, categorization of GI projects, design approaches, and recognition in the transportation realm.

As a result, the report team recommended that AASHTO, in conjunction with FHWA, develop a national GI definition as it relates to transportation for consistent adoption throughout the country – one also be incorporated into “A Policy on the Geometric Design of Highways,” which is known colloquially as the “Green Book.” 

Steve Sisson – a design resource engineer with the Delaware Department of Transportation and member of the AASHTO Technical Committee on Hydrology and Hydraulics – believes there are several other areas where more GI information could be included in AASHTO documents. 

He pointed to two current AASHTO publications – Highway Drainage Guidelines (HDG) and Drainage Manual (ADM) – currently undergoing updates to incorporate GI and new stormwater management (SWM) systems earlier into the infrastructure design process. Those particular areas include advancing setting-based site assessment, runoff reduction opportunities, and public private partnerships.

“The latter also will include support for more watershed-based approaches that minimize long term maintenance costs while increasing return on investment for public and private dollars,” Sisson explained.

“[Those] updates will draw on additional studies like NCHRP Research Report 840, ‘A Watershed Approach to Mitigating Stormwater Impacts,’ and NCHRP 25-60. ‘Watershed Approach to Mitigating Hydrologic Impacts of Transportation Projects,’” he said.

Sisson added that the GI section would also include an expanded generic Best Management Practices or BMP library, applicable over a wide range of regulatory jurisdictions, incorporating maintenance and construction recommendations.

The other recommendations made by the report team include:

  • Maintenance: Considered the most important project-related category identified for the success of GI, the teams believes in integrating maintenance plans incorporating GI elements into all transportation projects. However, training is needed to ensure proper workflow and actions for the GI solutions. Personnel with the right expertise and equipment are essential, along with policies, procedures, guidance, and manuals with standard operating procedures and maintenance plans to ensure long-term consistency in practice.
  • Watershed Approach versus Project Site Approach: GI solutions are often not available as an option when constrained by right of way or ROW on project sites. State DOTs typically obtain ROW in linear segments in alignment with the roadway, which can limit the opportunity for some GI practices, such as bio-retention areas, because there is not enough space within a linear ROW for effective treatments to be built. By taking a watershed approach and partnering with other agencies, the area for building GI is greatly increased. It is important for state DOTs and regulating agencies to develop common goals and outcomes for a watershed approach as well as educate practitioners on the benefits.
  • Information Sharing: The team identified a lack of generally available education, training, and research for interested agencies on the use of GI.  While there is a considerable amount of information about SWM and GI, there is no central repository or clearinghouse for that information and research. The team recommends development more GI based conferences, peer exchanges and a data repository located on a free website to encourage the implementation of more GI solutions.
  • Public Outreach: Public and political support is important for acceptance GI infrastructure solutions as well as to obtaining funding for those solutions. Educating the public on the importance of GI to clean water and clean air shows both them and decision makers the environmental, social, and economic benefits. The team recommended that state DOT public information officers or communications experts develop a “GI factsheet,” relevant signage, and other materials to provide the public with a good understanding of the locations and importance of GI.
  • Asset Management: State DOTs track highway assets such as bridges, barrier rail, and pavement miles, but currently stormwater and GI are not necessarily included in geospatial tracking systems. Including GI in the general agency-wide asset management system allows a state DOT to report to regulatory agencies the types and quantities of GI components that are in place for stormwater controls. It also allows an agency to plan and budget for necessary maintenance staff, inspections, materials, supplies, and scheduling.
  • Design: GI and components often do not have a standardized design within DOTs. Design guidance would vary somewhat according to regional and local geography and climatic conditions, each state could develop standard criteria and design guidelines in order to prevent having to develop designs strictly on a project-by-project basis. 
  • Construction Inspection: Vegetation establishment is a consistent challenge on transportation projects and issues that include process quality control, contractor compliance with specifications, and contractor and state DOT field personnel understanding of the overall re-vegetation process and specifications. The report team would like to see development of a process for ensuring correct implementation of permanent and temporary stormwater and GI features. The process would also include sequencing/time frames (e.g., contract hold points) for critical work and vegetation establishment. The team also recommended that standardized, recognized infiltration tests, such as ASTM standards, would be necessary for a successful program.

Overall, the report team believes that by using a holistic approach incorporating recommendations from those eight concentration areas, transportation agencies can provide long-term successful GI solutions to their roadway project. 

Two cyclists riding bikes on a bike lane.

WSDOT Issues Part One of Statewide Active Transportation Plan

The Washington State Department of Transportation recently made its new “Washington State Active Transportation Plan, 2020 and Beyond: Part 1” available online as part of its efforts to support more transit, bicycle, and pedestrian options.

[Above photo by WSDOT]

The plan assesses the needs for accessible pedestrian and bicyclist facilities, highlights safety concerns and provides the first-ever examination of state right of way and its suitability for active transportation.

WSDOT released a draft of part one of the plan in December 2020 and received more than 630 responses during an eight-week comment period. Those comments helped WSDOT identify policy topics for part two of the plan, scheduled for release later in 2021.

More people than ever are walking and bicycling statewide, according to WSDOT’s multimodal transportation dashboard, both as alternatives to transit use and to maintain physical and mental health during the pandemic. At the same time, “vulnerable road users” such as bicyclists and pedestrians now make up about 21 percent of all traffic deaths – far out of proportion to the fatality rates for other modes of travel, noted WSDOT Secretary Roger Millar.

“Whether you drive, bike, walk, or roll, the state’s highway rights-of-way serve as the backbone of our transportation system,” he said in a statement. “In the engagement for this plan, we heard very clearly that state routes need to connect people, not separate them. With this plan, we have new understanding to help us work with our partners to create complete, safer, and more accessible networks for each and every one of us, regardless of how we get around.”

Part one of the plan addresses those steadily increasing vulnerable road user fatalities and identifies driving speed and roadway crossings as top factors. It also:

  • Examines the effects of past infrastructure decisions on safety and mobility, particularly in places where those decisions affected transportation access and health.
  • Provides a first-ever needs assessment of the state system for active transportation use and estimates the cost of improvements in population centers.
  • Describes the concept of statewide bikeways and trails network.
  • Offers using “level of traffic stress” as a data-based evaluation tool for state right of way and population centers when analyzing the effects of land-use change. Level of stress is a method to objectively measure roadway characteristics that affect people’s ability to use active transportation.  

Maryland DOT P3 Project Building Stormwater ‘Smart Ponds’

The Maryland Department of Transportation recently unveiled three “smart ponds” built via a public-private partnership or P3 stormwater control project that seeks to reduce pollutants and curb local flooding.

[Above photo by Maryland DOT

The agency said this “smart pond” project is the first of its kind involving a state transportation department and it involved the Maryland Department of Environment, Environmental Protection Agency, Walmart, and The Nature Conservancy.

The Maryland DOT said this “smart pond” technology – developed by Opti – uses sensors and software to monitor real-time conditions such as water level and storage volume. Then, using Internet-based weather forecasts, the system remotely operate valves that control timing and volume of water discharge from the ponds as longer retention time increases water quality by capturing more sediment and nutrients.

Thus, when rain is in the forecast, the system can automatically open valves to drain the pond prior to precipitation, the agency said – helping maximize stormwater storage efficiency and reducing downstream flooding.

“These smart ponds are another innovative way we’re working to improve the communities we serve,” explained Greg Slater, Maryland DOT secretary, in a statement. “We’re being responsible stewards of the environment while at the same time helping protect the infrastructure that supports our hard-working residents and businesses.”

The Maryland Environmental Service, The Nature Conservancy, and Opti originally signed a contract in July 2020 to retrofit three stormwater runoff ponds located at Walmart stores as “smart ponds.” Concurrently, the Maryland DOT plans to spend $3.25 million to purchase 80 acres worth of Chesapeake Bay impervious area treatment credits generated by the smart ponds at Walmart. After certification of the credits, the Maryland DOT will begin purchasing the credits this spring. 

The agency said this smart pond partnership represents the first time a state department of transportation is purchasing credits from a Water Quality Trading Program. Maryland’s program created a water quality marketplace for credits generated by pollutant reductions elsewhere in Maryland’s portion of the Chesapeake Bay watershed – offering “market-based” economic incentives for pollutant reductions. 

The cost to Maryland DOT for these new credits is about $37,500 per acre, including installation of smart pond technology and 20 years of monitoring, inspecting, operating and maintaining the ponds by The Nature Conservancy and Opti. That is significantly less than the average construction cost of $150,000 per impervious acre treated through stormwater control devices such as swales, bio-retention cells and stormwater ponds, the agency noted – and that $150,000 cost does not include operation and maintenance. Overall, the Maryland DOT said it owns about 800 ponds that could benefit from this smart pond technology. 

Mug shots of Sens. Schumer and Sherrod

Senators Unveil $73B ‘Clean Transit for America’ Plan

Two key Senate Democrats introduced a $73 billion plan on May 4 to transition the nation’s transit buses and vans to Zero Emission Vehicle or ZEV platforms.

The “Clean Transit for America” plan – introduced by Sen. Chuck Schumer, D-N.Y., the senate’s majority leader, and Sen. Sherrod Brown, D-Ohio, chairman of the Senate Committee on Banking, Housing and Urban Affairs – would replace America’s 70,000 mass transit buses and 85,000 cutaway/transit vans to “clean energy vehicles.” The plan would also prioritize funding for areas with the worst air quality first.

Currently in the United States, only 2 percent of buses are ZEVs, argued Sen. Schumer in a statement. He added that the volume of air pollutants from diesel buses disproportionally affects low-income communities and communities of color. 

“To reduce the carbon in our atmosphere and address the climate crisis, we must transform our transit system,” he said. “The Clean Transit for America proposal will replace dirty, diesel-spewing buses, create new American jobs, help save the planet and protect public health, particularly in our country’s most vulnerable communities.”

“Americans deserve world-class public transportation that is delivered with modern, zero-emission buses built by American workers,” added Sen. Brown. “The Clean Transit for America Plan will create a significant number of good-paying, union jobs building zero-emission buses in the U.S. It is the kind of transformative investment we need in public transit that will put Americans to work [and] connects people with opportunity.”

In a related effort, Sen. Tom Carper, D-Del., recently outlined a “vision” for how the Environmental Protection Agency could adopt standards to reduce greenhouse gas or GHG emissions in the automotive industry and eliminate tailpipe pollution from new cars by 2035.

“The future of the automobile manufacturing sector is at a crossroads,” Sen. Carper – chairman of the Senate Committee on Environment and Public Works – explained in a letter to EPA Administrator Michael Regan.

“The Clean Air Act provides sufficient authority for the EPA to rise to this challenge,” he said in a statement released with the letter. “EPA can establish requirements on new cars that would significantly reduce air pollution harming communities, put the nation on track to maintain its leadership in vehicle technology, and make significant progress in fighting climate change.”

Sen. Carper added that “if the U.S. does not establish a robust policy that leads to ZEV deployment” he warned the nation “will be at risk of losing our automotive jobs and industry leadership to other nations, as well as enduring unnecessary public health impacts from pollution.”

Environmental News Highlights – May 12, 2021



A roundup of headlines curated for state transportation environmental professionals


In Louisiana, Biden makes infrastructure pitch local – NBC News

McConnell says GOP open to $600 billion for infrastructure – AP

“Long overdue”: The Senate just passed $35 billion for clean drinking water – Grist

Agricultural exporters want DOT to address shipping challenges – Capital Press

EPA leader connects recycling and environmental justice – Resource Recycling

Women Break Ground in Shaping Infrastructure Plans in Congress – Bloomberg Government


MTA to restore 24-hour subway service as New York City prepares to fully reopen – Fortune/Bloomberg


Bipartisan Legislation Introduced to Bolster Resiliency of U.S. Ports – Homeland Security Today

The Dakota Access Pipeline faces possible closure – Reuters

Statewide campaign highlights need for investment in Missouri’s transportation infrastructure – Ozark Radio News

‘It’s time to finally fix our damn roads’: Polis, Colorado state legislative leaders announce transportation bill – KUSA-TV

Implementing CHANGE in Vermont – FHWA Innovator

Micro, electric and car-free: Nine takeaways from CNN’s panel on the future of urban transport – CNN


Updated EV Bill Seeks to Electrify America’s Highway System – AASHTO Journal

Entire U.S. transit bus fleet could transition to zero emission at a cost of $56 billion to $89 billion – Mass Transit

Legislation Would Start Rhode Island Down Road to Reduced Transportation Emissions – ecoRI

As ‘diesel death zones’ spread in California, pollution regulators place new rules on warehouse industry – Los Angeles Times/Tribune News Service

As a transportation choice ride-sharing found to be less ‘green’ than walking or public transit – Air Quality Matters (Commentary)


Transportation Equity and Minnesota’s Rethinking I-94 Project – AASHTO ETAP Podcast

Memphis pipeline faces environmental justice reckoning – E&E News


Why California Is Planning to Ban Fracking – New York Times

Controversial hazard tree removal project sparks protests – East Oregonian

Roadside Litter Collection Soars Past 5 Million Pounds – North Carolina DOT (Press release)


Sartell wants to reopen historic bridge over Mississippi River to pedestrians, bikers – Bring Me the News

Scenic Route guide provides 8 ways artists contribute to equity-driven transportation projects – Kresge Foundation

Free To A Good Home: An 83-Year-Old Western Colorado Bridge – CPR News

How a $180 Million Parking Lot Could Change N.Y.C.’s Historic Character – New York Times


Ozarks transportation group proposes 45 miles of new trails by 2045, asks for public inputSpringfield News-Leader

Legislation classifies electric-assist bikes as bicycles, not motorcycles – WCAX-TV

‘Capital to Coast’ campaign stops in Macon – WMGT-TV

Ross County Health District’s new transportation plan seeks to improve safety and mobility – Chillicothe Gazette

The Scoop with Amy Doyle: ‘Mobility’ – a buzzword whose time has come – Greenville Journal (Commentary)

Active Transportation Plan: A new compass to guide the state’s active transportation future – Washington State DOT (Press release)


Untangling Major Societal Issues on the Road to Environmental Health – TRB

The Future of Mobility Summit – The Hill

2021 Transportation Summit: Revisiting the Urban Interstate: Freeway to the Future, or Road to Ruin? – Move Minneapolis


Notice of Funding Opportunity for Environmental Mitigation Pilot Program – FAA (Notice of funding opportunity)

Modernization of Coast Guard Base Seattle; Preparation of Programmatic Environmental Impact StatementCoast Guard (Notice of intent to prepare a Programmatic Environmental Impact Statement; notice of virtual scoping; and request for comments)