Spring 2024

Ella Alford, "The Opportunities for Sustainable Transportation in the US, Lessons from Europe"

(Cover image sourced from bluejayphoto/Getty Images)


Communities in the United States are struggling to increase the environmental, economic, and social sustainability of their transportation system. The article finds that US cities and communities often lack sustainable transportation because of urban sprawl and dependence on private vehicle use. Next, the article analyzes how the German city of Freiburg increased the sustainability of its transportation system. The analysis touches on walkability, biking infrastructure, and availability of public transportation throughout Freiburg, along with less private vehicle use. The article identifies how Freiburg meets the three pillars of sustainability and how the US falls short. The article then gives suggestions for how US cities and communities can reach a more sustainable transportation system. This part of the analysis is based on a site visit and interviews with urban transportation experts in Freiburg during a study abroad program in the Summer of 2022. Literature searches are utilized throughout the article for evidence and background information. The article ends with a recommendation and an evaluation of lessons from Freiburg for US cities.

Keywords: Sustainability, Environment, Transportation, Europe, United States, Infrastructure

1. Introduction

        Transportation is a critical part of any society. It is how a passenger gets from point A to point B, and in many American cities, the main means of transportation is by car.  This dependence is a significant factor holding many US communities from meeting economic, environmental, and social sustainability goals. These goals are referred to by urban planners as the three pillars of sustainability, which brings long-term livability for its citizens when achieved. The three pillars described by Dr. Ben Purvis are “commonly represented by three intersecting circles with overall sustainability at the centre [sic]” (Purvis 681).

        Environmental sustainability refers to local and global air pollution and other environmental damage. Transportation can reduce its environmental and air pollution through greater use of public transportation, biking, walking, and less driving. Economic sustainability refers to the monetary cost of building, maintaining, and operating a transportation system. This can be personal or governmental outlays, regardless, it asks if monetary benefits outweigh the costs. Some financial questions could be related to the economic benefits of a new public transportation system or the cost of a new car for a household. Lastly, social sustainability concerns public health, the happiness of a society, opportunities, and social justice. It asks, are car-dependent societies fair, just, and equal when not everyone can afford a car? It considers what opportunities lower-income individuals are missing without access to a private vehicle. These are concerns and questions we must consider as a nation. Looking at other societies that have achieved a more environmentally sound, economically efficient, and socially equitable transportation system may provide lessons for communities in the United States. In particular, US communities may be able to learn from cities that have achieved more sustainable models.

        Freiburg (230,000 inhabitants), often dubbed Germany’s most sustainable city, is one such place. Freiburg features a multimodal public transportation system that has a trolley system as its backbone, plentiful bike lanes, and walking infrastructure that is safe and accessible. In addition, Freiburg makes car ownership and usage difficult and enforces strategies like traffic calming to increase bike use. This is exceptional in comparison to most American cities, whose transportation system is dependent on private car use. In a perfect world, the US would simply implement Freiburg’s transportation policies, yet it is impossible because of path dependence of policies and suburban sprawl. Suburban sprawl is described as “low-density residential housing, single-use zoning, and increased reliance on private automobiles for transportation” (Rafferty 1). Suburban sprawl encourages and enables a car-dependent environment. While US communities cannot simply incorporate Freiburg’s system, mirroring their policies could still make ground toward reaching an accessible transportation system that is more eco-friendly, cost-effective, and just.

        The methods used in this article include literature searches, analysis of government documents, meetings with local transportation and land-use experts, and site visits. The site visit to Freiburg was part of a study abroad course in the Summer of 2022 with visits to other European cities including Zurich, Budapest, Prague, Vienna, Strasbourg, and Lugano. While not part of this study, experiences in these other cities provided a background and helped me determine that Freiburg was the best example of achieving (or getting close to) the three pillars of sustainability. While in Freiburg, I met with multiple academics and practitioners to further my understanding of the city for this comparison. This article will outline Freiburg’s transportation policies, their significance to US communities, and present a critique on how to move forward in American cities.

2. Pillars of Sustainability

        The three pillars of sustainability: environmental, social, and economic, have equal importance for achieving full sustainability. The environmental dimension entails reducing CO2 emissions through increased public transit use, walking, and bicycling, combined with decreased private car use. The social dimension looks at society and public health of transportation systems such as the benefits that biking has for overall human health. Social sustainability can also play a role in equal and fair opportunities for societies dependent on private car use. If not everyone in society can afford a car, then travel-based opportunities are limited by a lack of accessible and affordable transportation.

        Economic sustainability ties in with the costs and benefits of transportation. An example is the high costs of owning and operating a private car. If a car is needed for accessing a workplace, but one does not make enough money at work to afford the car, then the costs do not outweigh the benefits. After all, how can an individual get to work to earn money in a car-dependent built environment? Another example is when a new public transportation method is installed or funded, it is asked, will the benefits outweigh the costs, will it be cost-effective, and will it result in economic growth? These questions are critical to determining the economic sustainability of public transportation.
        The criteria that sustainable transportation needs to meet fall under these three pillars. If transportation works to help lower the CO2 impact, then it can be deemed environmentally sustainable. If a transportation mode is socially more equal and fairer, then it is socially sustainable. If a transportation mode’s benefits outweigh the cost, then it is economically sustainable. If a transportation system meets all three of these standards, then it is fully sustainable.

2a. How Freiburg Meets the Three Pillars of Sustainability

        Freiburg, Germany has increased the sustainability of its transportation system over the last decades. One measurement for the improvement of Freiburg’s transportation system is the high share of daily trips made by public transit, biking, and walking. Below is a graph that includes the percentage of daily trips taken in Freiburg, compared to the average of US cities of comparable population size.

Figure 1 Sustainable Transportation in Freiburg vs. Average US Cities

(Buehler & Pucher 50)
        As shown in Figure 1, Freiburg has significantly higher percentages of trips by public transit, cycling, and walking when compared to US cities of similar population size (~200k inhabitants). Freiburg achieves this mode split in a few diverse ways. First, the city has an accessible and understandable trolley system that serves the entire city (ERBD Green Cities Policy Tool 1). The trolley reduces driving, thus lowering CO2 emissions from private vehicles. The trolley is electric and powered entirely by renewable energy, removing gas and oil consumption, both large contributors to climate change.

        Freiburg also emphasizes biking. In 2017, Freiburg had the most bike use in Germany as measured by data provided by Eco-Counter—a company with bicycling counters throughout Europe. With 3.4 million bicycle trips counted in 2017 and Freiburg having twice as many bicycles as cars, they earned the title ‘bicycle capital of Germany’ (Eco-Counter 1). Incentives that civic leadership incorporated include:        These methods are environmentally sound because they reduce private car use and increase the attractiveness of bicycling – an alternative that emits less greenhouse gases. Freiburg is a city with little urban sprawl and with frequent short trip distances, which helps all three non-automobile modes of transportation, especially walking. Freiburg combined policies that limit suburban sprawl with planning and design that promote greener and more efficient infrastructure and transportation, “using planning and design, it created a ‘city of short distances, enabling high levels of public transit use, cycling and walking. Investment in the transit system measures to encourage cycle use were coupled with restrictions on car use through road design and traffic and parking management measures” (ERBD Green Cities Policy Tool 1).

        Furthermore, when looking at the standardized sprawl index (SNDi), Freiburg, Germany scored around 0.8 and the source says, “a higher SNDi means less-connected streets – i.e., more sprawl. For the 10137 cities in our dataset, the average SNDi is 2.25, with half of the cities' SNDis falling between 1.08 and 3.25” (SNDi Trends 1). Freiburg is a compact city with little suburban sprawl making it fairly walkable. In addition, Freiburg has streets in the city center where cars are not allowed, making the city center safer and more convenient for pedestrians. Walking is the most environmentally sustainable form of transportation, as there are few greenhouse gas emissions involved. Overall, Freiburg’s efforts to increase bike use, walkability, and convenient public transportation make their transportation system environmentally sustainable.

        Freiburg’s transportation system is socially sustainable as well. For example, Freiburg’s emphasis on biking benefits the health of the public through physical activity. When meeting with Dr. Florian Schneider (City of Freiburg), he talked about people reporting that they feel happier and more productive when biking to work compared to driving. Biking is positive both for physical health and mental health, as it releases endorphins. This leads to a better lifestyle. Furthermore, Freiburg’s accessible and affordable public transportation system brings new opportunities for people and reduces the need and use of private cars. The cost of owning and operating a private vehicle may hold people back financially; therefore, accessible and affordable transportation reduces the need for and use of private cars.

        With fewer financial obstacles, more opportunities arise for people who are not able to afford a car. The individuals who cannot afford a private vehicle will face fewer transportation obstacles when searching for new opportunities in Freiburg, like a new job. They will worry less about physical proximity to these new opportunities because of their access to public transportation that can get them where they need to go for an affordable cost. The use of public transportation doubled in Freiburg between 1990 and 2010, the yearly number of bicycle trips also doubled and in Vauban, a new sustainable infill development in Freiburg, more than 70% of households do not own a private vehicle (EBRD Green Cities Policy Tool). This is socially sustainable because economic factors involving transportation have less influence on new opportunities, creating fair and equal opportunity regardless of social class and access to private vehicle use.

        Economic sustainability is evident in Freiburg’s transportation system as well. With less of a need or use for private cars, there is less land dedicated to parking spaces, freeing up more space to develop for housing and bringing in more wealth and economic growth. Less need for a car saves people money they would have spent on a car or gas. The trolley and biking are cost-effective options when compared to the expenditures for private vehicles, which means more money in citizens’ pockets to spend, invest, or pay taxes.

        Furthermore, Germany has higher gas taxes than the United States, “revenues from gasoline taxes and vehicle registration fees in Germany have covered an increasing share of federal, state and local government expenditures on road construction and maintenance—rising from 92% in 1975 to 259% in 2006” (Buehler & Pucher 47). These high and rising gas taxes keep the roads in good condition but also disincentivize private car use. Overall, these incentives for walking, cycling, and public transportation help achieve economic sustainability in Freiburg’s transportation system through the disincentivized use of private vehicles.

2b. How the United States Communities Fall Short on the Three Pillars of Sustainability

        Transportation systems in most US communities fall substantially short when compared to Freiburg environmentally, economically, and socially, primarily due to the United States' dependence on private vehicles. In the US, “nearly all adults regularly drive a car or other vehicle, with 83% reporting they do so personally at least several times a week. This includes 64% who say they drive every day” (Brenan 1). Suburban sprawl in the US further complicates walking, cycling, and public transportation usage because Americans have farther distances to travel to reach their destinations of daily life compared to those in Freiburg. Additionally, in most places, there is no reliable public transit system, nor is biking as incentivized or safe as it is in Freiburg. For example, the US has much higher fatality and injury rates per kilometer per year for pedestrian, bicyclist, and motorist deaths compared to European countries (Buehler & Pucher 37). This is yet another hindrance the US faces when striving toward sustainable transit, biking, and pedestrian safety.

        To delve deeper into the issues, many US communities fall short environmentally, socially, and economically in their transportation system. Environmentally, the US dependence on private car use contributes roughly 58% of the share of US Transportation Sector GHG Emissions by Source in 2021, while overall transportation emissions in 2021 make up 29% of the share of the US GHG Emissions by Economic Sector (EPA Fast Facts 1). This translates to passenger cars making up 18.6% of the Transportation GHG Emissions yearly in 2021 (EPA Fast Facts 2). This is a considerable contribution to climate change, especially because the US is the second largest contributor to climate change globally. Socially, lower-income individuals in the US face extreme obstacles when it comes to transportation to new opportunities. Evelyn Blumenburg, PhD in Urban Planning, UCLA, conducted studies examining the role of automobiles in Moving to Opportunity (MTO) households. Her findings showed that automobiles “provide households with better access to opportunities than other modes of travel” and that “automobile access reduces households’ neighborhood poverty exposure by between 3% and 4%” and that to reduce poverty within households they suggest providing access to a car (Blumenberg 1).

        Without a car, there is less access to opportunities because individuals do not have a mode of transportation to get to the opportunity. Blumenberg’s findings prove exactly this, therefore a dependence on private car use in America is not socially sustainable. Lastly, economically, the average US family spends $3,605 a year on auto loans, with annual average spending on household bills of $22,668, making auto loans the third highest category of expenditure, below mortgage and rent (U.S. Auto Loans Market Size and Household Spending Report 3). A car in America is not a cost-friendly necessity, especially when other first-world countries do not require this kind of bill. An example would be Switzerland, which was ranked to have the highest cost of owning a car in Europe at 1,313 Euros ($1,408) in 2022 (Statista 1). This shows that even the highest average automobile bill in Europe is still half of the average American’s household bill, proving many other first-world countries are not facing the same inflated costs of private transportation as the US does. These obstacles are less prevalent in Freiburg, and other parts of Europe, because of their lack of urban sprawl and effective urban infrastructure.

3. Challenges of Transportation Infrastructure in US Cities

        The challenges the US faces with adapting its transportation system are great, but not insurmountable. While cities in America cannot fully embody the structure of Freiburg, the lessons are transferable, especially in some cities, like Chicago, New York, and other higher density areas. Even lower density rural towns could invest in traffic calming and bike routes, encourage walkability with green infrastructure, and provide a local trolley or bus. Just some of these solutions listed here can disincentivize car use and promote the three pillars of sustainability.

        Considering future infrastructure, different communities in America could disincentivize urban sprawl with policies that foster denser environments with a greater mix of land uses, this would help final destinations be more accessible by walking or biking. The denser US cities could take a lesson from Freiburg’s trolley that goes throughout the entire city and offers a good public transportation alternative for most trips. These efforts would help reduce the use and reliance of cars. Dr. Florian Schneider, Transportation Planner for Freiburg, said that traffic calming would be the most viable alternative when looking at how to increase sustainable transportation in America. This effort would also help American communities encourage non-automobile transportation because it would make the roads safer for cyclists and disincentivize private car use. Buehler and Pucher state, “reduced speeds are crucial in enabling motorists to avoid crashes with pedestrians and bicyclists and in increasing the likelihood of a non-motorist’s survival in a crash” (Buehler and Pucher 39). This may be another reason why Americans choose to drive instead of walk or bike because in some cases, it may feel and be safer.

3a Benefits of Current American Infrastructure

        The US can learn lessons from Freiburg, but there are still benefits to the current American transportation system. With societies centered around cars comes easier access to more spread-out areas. In America, a drive to the store and back can be quick, and easy (during off-peak times). There are little to no traffic-calming measures decreasing the driving time, and there is a parking lot directly outside the destination in most occurrences, for less walking time. While this is time efficient and makes getting places easy, it is not environmentally friendly because private car use is a contributor to global climate change. It also enforces and encourages urban sprawl which will only exacerbate this issue. It is not socially sustainable because not all Americans can afford cars, and not economically sustainable because cars are expensive.

        A critique of the Freiburg transportation system is that it may be more difficult to get around for persons with disabilities, although neighborhoods with calming traffic have better sidewalks for wheelchair access, curb cuts, and shorter crossing distances. Electric wheelchairs can also use the facilities designed for bikes. There is a website surrounding living in Freiburg that has a section regarding barrier-free living, handicap services, shopping and care services, and more, making handicapped living in Freiburg accessible (Freiburg Fur Alle). While there are benefits to transportation in America, there are heavier costs, climate change, less opportunity for lower-income individuals, and a heavier economic burden. The long-term benefits of the German transportation system in Freiburg strive toward the three pillars of sustainability and a better lifestyle for those in Freiburg.

4. Conclusions

        Freiburg has achieved a more sustainable transportation system, primarily because of their containment of suburban sprawl which allowed them to enforce and create a sustainable infrastructure, meeting the three pillars of sustainability. Within their city, they successfully enforce traffic calming to reduce private car use, as seen in the low use of private vehicles. The walkability and efficient bike infrastructure of Freiburg also allowed for better public transit infrastructure, reducing the number of car trips necessary. Lastly, the public trolley that runs throughout the city reduces the need for private car use as well, as an easy and affordable alternative. Freiburg meets the three pillars of sustainability and leads by example to other cities and countries around the world.

        As a first step, US communities that want to increase their transportation sustainability could begin by working on traffic calming measures. This would disincentivize car use. To further the effectiveness of traffic calming, US communities could invest in better public transportation like buses, metros, and trolleys. Another motive that US communities could include would be to focus on the walkability of their cities and reduce urban sprawl as cities grow. These measures would begin to disincentivize cars and promote a transport system with more environmentally friendly, economically efficient, and socially equitable qualities.

        There is still a long way to go, but it is possible. Cities and communities in America can utilize lessons and examples from Freiburg in their transportation system to strive toward reaching the three pillars of sustainability. It is important for US communities to begin to make these changes to foster a more sustainable society. With a more sustainable transportation system, US communities will offer more opportunities to be socially sustainable, lower their CO2 emissions to be environmentally sustainable, and save money to reach higher economic sustainability. These changes will improve governance and be a greater benefit to society.

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