Green Infrastructure: The Forgotten Part of a Climate Change Agenda

CC Image courtesy of Washington State Department of Transportation on Flickr

Infrastructure is a forgotten topic in this country. When you see polling of important issues to Americans, it is usually left off the list entirely so it has to be manually added in the “Other” category if provided. Yet, we all realize that without roads specifically, we wouldn’t be able to travel as efficiently nor receive the goods and services that we do now.

I don’t believe flying cars will exist in the mainstream in my lifetime, so that means over the next 40 years or so, we’ll need to figure out what to do about our unsafe and crumbling roads.

We also have the challenge of climate change, which is why in addition to the “infrastructure” buzzword that many politicians like to bring up but never elaborate on, they’ve added the word “green” in front of it as if that automatically solves the problem.

So let’s talk about what the challenges, opportunities and solutions that currently exist around “green infrastructure.”


I mention funding first, because this is the ultimate issue that Congress hasn’t really budged on since the 1990s, leaving states to find their own solutions. The federal fuel tax on gasoline along with a tax on diesel fuel, are the primary funding sources of the Highway Trust Fund which is what is used for all federal surface and transit transportation programs in the United States. The last time the federal fuel tax on gasoline was addressed was in 1993 when it was part of President Clinton’s solution to reduce the federal deficit. 4.3 cents was added for that purpose bringing the tax to 18.4 cents per gallon. The 4.3 cents was then redirected to the Highway Trust Fund in 1997 where it has stayed.

Meanwhile, the fuel efficiency of vehicles has increased since 1993 due to consumer demand, reducing the revenue collected by this fund to the point where it was forecasted to be insolvent multiple times. Congress came up with supplemental revenue each time, but never adjusted the mechanism by raising the tax or finding a sustainable solution. President Obama had also reached an agreement with automakers in 2012 to increase efficiency to 54.5 miles per gallon by 2026, which would obviously be great for consumers, the environment, and would help the United States free itself from reliance on foreign sources of oil. However, this agreement would also cause a future loss of revenue of billions of dollars for the Highway Trust Fund.

The Trump Administration rolled back these standards in 2018 and set a target of 37 miles per gallon by 2026, but the problem of the funding mechanism of the Highway Trust Fund remains and the Fund is expected to be insolvent once again by the end of 2021.

Hybrid, electric, and eventually alternatively fueled vehicles such as those powered by hydrogen fuel cells are the future of American vehicles as part of a big solution to climate change. However, the roads that all of these vehicles use depend on funding mechanism of fuel taxes to upgrade and maintain. Thus, addressing climate change is now in direct conflict with funding safe and reliable infrastructure.

There are multiple solutions to this conflict.

The easiest solution is to raise fuel taxes which multiple states have already done in the last few years. With other methods taking likely years to implement and provide the same revenue, the fuel tax is the only option for an immediate influx of revenue that provides the smallest everyday impact to consumers. Gasoline prices are so volatile, if the tax was not known, most would likely never see the difference and meanwhile millions would be raised for each state. At the federal level, it has been estimated by the Congressional Budget Office that each 1 cent increase in the tax would raise $1.8 billion in 2020 but fall to less than $1.7 billion in 2029 due to the increased fuel efficiency of vehicles. However, with a need to phase out fossil fuels in the next few decades and a continuing decline in revenue based on the increase in fuel efficiency and hybrid and alternative fueled vehicle use, an increased fuel tax is only a temporary solution.

For a longer term, sustainable solution, user fees for vehicle miles traveled are becoming more popular and may be the best alternative. The Federal Highway Administration (FHWA) recently issued $10.2 million in grant money to seven state departments of transportation to study alternatives to the fuel tax and the majority are using it to study user fees.

Oregon was one of the states awarded a grant and it has had the user fees in place the longest, with a pilot in 2006 and again in 2012. Those pilot projects have led to the OReGO program that users can now sign up for. With OReGO, mileage is tracked with a device provided with a service of the user’s choosing and then all fuel tax paid is subtracted while mileage is paid for at 1.7 cents per mile traveled. Users can either prepay with Azuga or post-pay with emovis directly or with a ODOT sponsored emovis service, both via a quarterly invoice.

California has also piloted user fees and together with Oregon, they are part of a 14 state coalition to further study the implementation of user fees, addressing out-of-state users as well.

Other funding options that exist involve tolling, fees on the bulk purchase of fuel, increased registration fees, and fees on electric, hybrid and alternative fueled vehicles.

Solutions at a state level are not preferable given the limitations of state budgets compared to federal dollars. Congress must act to ensure the Highway Trust Fund is solvent, and to also find a sustainable alternative to fuel taxes so that the United States can address climate change while providing adequate funding for the needs of its highway system.


CC Image courtesy of Pam Broviak on Flickr

Another overlooked fact that with phasing out of fossil fuel use in America, the materials that we currently use to build roads will also become scarce and therefore extremely costly.

An estimated 94% of roads in the United States are currently paved with asphalt pavement. The asphalt is used as a binding agent to coat and hold aggregate together and together the mix serves as a flexible pavement. Asphalt is a waste product of the crude oil refining process, something that is contributing to climate change, especially with the methane gas that is released. Asphalt prices have also continued to rise and have caused states to delay or cancel projects as a result. If it continues to become more scarce, its cost will continue to rise and highway construction will be adversely affected given current funding levels so an alternative must be found.

Concrete is the next best alternative, but it is also not environmentally friendly to produce with the need for water and the carbon that is released in production. Concrete pavement is also more expensive and time consuming to construct than asphalt pavement.

So what other alternatives currently exist?

Recycling asphalt pavement has been an option for the past few decades, but the recycled asphalt is only used for a base, and typically requires new asphalt to be introduced into the recycling process. It also requires a surface layer of hot mix asphalt pavement for a final wearing surface, so it still largely depends on asphalt.

The University of California at San Diego integrated plastic waste into asphalt pavement for a project on campus. MacReber, a company from the UK who developed the design, insists that that all the plastic is melted into the asphalt and no microplastics can be released. If true, while not an alternative to asphalt pavement, it reduces the amount of asphalt necessary to produce a pavement mix while ridding the country of harmful plastic waste. Dow Chemical also integrated plastic waste into a road paving project at their plastic manufacturing plant in Lake Jackson, Texas.

Recycled plastic waste has also been used in pavement mixes in India, Australia and the UK.

Besides integrating plastics into the mix design, there is currently an effort to explore roads made entirely from plastic. Three companies in the Netherlands — KWS, Wavin and Total — are working on a plastic modular road building system called PlasticRoad. With PlasticRoad they claim it will cut construction times by 70%, and last three times as long as asphalt pavements. PlasticRoad also uses recycled plastic in the material. The companies have used the product to create bicycle paths in two Dutch cities: Zwolle and Giethoorn.

In any case, while some colleges and companies are looking at specific solutions, there is far too little research in the United States being done to study green alternatives to asphalt and concrete given our need to phase out fossil fuel use and reduce our carbon footprint. This should be a priority for FHWA under the next administration.

Green Intersections

Projects at intersections that reduce vehicle idling times can lead to less emissions and fuel consumption which will help reduce the effects of climate change. The transportation sector emits 1.9 billion metric tons of carbon dioxide annually with nearly 1.1 billion of that coming from motor gasoline consumption.

The best example of a green intersection project is a roundabout. As I wrote about in a previous story, roundabouts are really the best type of intersection that exists today because of the safety and environmental benefits.

A 2003 study by Kansas State University found the following reductions in emissions at roundabouts compared to stop-controlled intersections:

  • 21–42% reduction in carbon monoxide emissions
  • 16–59% reduction in carbon dioxide emissions
  • 20–48% reduction in oxides of nitrogen emissions
  • 18–65% reduction in hydrocarbon emissions

Fuel consumption has also been measured to be reduced at roundabouts with the city of Carmel, IN estimating that each roundabout they have saves 24,000 gallons of fuel consumed per year.

Roundabouts also offer the ability to provide green space in the central island and splitter islands for various landscaping to remove more carbon dioxide from the air.

However, there seems to be more of a focus in some states on upgrading signals to become integrated with vehicle information systems and eventually autonomous vehicles to reduce the amount of idling time at signalized intersections. So called “smart signals” would require expensive upgrades and with sensors, more additional maintenance over the lifespan of the technology which would also need to be upgraded over time. With a signal completely dependent on electricity to function and requiring infrastructure susceptible to wind or ice damage, they are also far less resistant to the effects of severe weather caused by climate change.

Roundabouts on the other hand are already autonomous vehicle ready and would rely on vehicle to vehicle communication (V2V) which would be upgraded in vehicles automatically over time. The only electricity required is to power pedestrian beacons and/or lighting of the roundabout, two secondary features that don’t affect the pure functionality of its operation unlike traffic signals. Signage and lighting would also be the only parts susceptible to wind or ice damage from severe weather.

A roundabout not only prevents adverse effects from climate change, but it is the most resilient intersection to the adverse effects of climate change. FHWA has currently listed roundabouts as an “innovative” instead of a “conventional” intersection, but given the benefits, some states have taken the initiative to make roundabouts the primary type of intersection considered with a signalized or stop-controlled option as the alternative. FHWA under the next administration should follow suit and adopt the roundabout as a conventional and preferred type of intersection in the United States as part of the effort to combat climate change.

There are many challenges for the future of infrastructure in the United States, especially with our vast network of roads and bridges. Our funding sources are currently a barrier to addressing climate change while continuing to address the needs of our highway system. While infrastructure has been an afterthought traditionally, and especially as we look at the 2020 election campaign cycle, it needs to be a key component of any climate change agenda. Only by providing alternative funding sources, green materials and design solutions such as roundabouts will the United States be able to completely address the climate challenge that we are currently facing.

Oregon Trail generation progressive, licensed professional engineer, advocate of roundabouts, transportation funding reform and member of organized labor.

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