Bike: for Your Earth, Health, and Community by Jessica Zhao

Growing up in a suburban town, I serpentined through my neighborhood streets every day after school. I also studied abroad in Copenhagen, Denmark and relied solely on public transportation and my bicycle, as it truly was the easiest and often fastest way to get around. These days, my bike offers both practical transportation to Duke’s campus and an escape from quarantine.

In Henry’s blog “Transportation without Pollution: How America Can Ditch Gasoline”, I was alarmed by the statistic that “over ¾ of workers in the United States drove to work by themselves in 2013, and an additional 10% carpooled”.[1] In contrast, nearly half of all commuters bicycle to school and work in Copenhagen, which boasts the most advanced and widely used network of bicycle lanes in the world.[2] Henry’s blog and my love of biking together inspired me to question our reliance on motor vehicles in the US and think beyond public transportation and car-sharing to a healthier, happier alternative.

The transportation sector is the largest contributor to U.S. greenhouse gas emissions at 31%, and electrifying vehicles alone is not enough to combat this source.[3] Even with Obama-era tax rebates and automakers signaling their shift to electric vehicles (EV), fewer than 1% of vehicles on the road today are electric.[4] Due to slow turnover rates of existing gas-powered cars and trucks, shifting to an entirely electric vehicle fleet by 2050 would require gasoline-powered vehicle sales to halt by 2035, a drastic and somewhat lofty goal.[5] Thus meeting Biden’s ambitious zero-carbon target by 2050 requires economy-wide infrastructure changes — and perhaps creative behavioral shifts in the ways we travel.

In addition to decreasing greenhouse gas emissions, biking could also alleviate health impacts and equity concerns related to our current transportation system.

One 2017 study also estimated that road transportation emissions “cause 53,000 premature deaths per year nationally”, making transportation the largest single contributor to premature deaths from air pollution, disproportionately affecting children, elderly, low-income people, and people of color (Twite). Obesity rates in the U.S. have also become a common, serious, and costly disease, affecting 42% of the adult population and costing an estimated $147 billion in medical costs.[6], [7] A different study with over 150,000 participants ages 40-69 found that when compared to driving, bicycle commuting offered the greatest health benefits; an active commute helped middle-aged adults decrease their body fat and meet recommended levels of daily physical activity.[8]

Where does the U.S. stand on bicycle infrastructure?

Following Europe’s example, U.S. cities have greatly increased their bicycle lane investments in recent years.

During the COVID-19 pandemic, electric bicycles also became a key strategy for essential workers and low-income populations to travel, shown through multiple pilot programs around the country. For example, the Colorado Energy Office awarded $500,000 in grants to such programs for essential workers and low-income communities. California’s Clean Cars For All program also allows disadvantaged households to trade in their used cars for a $7,500 voucher towards purchasing an electric bike.[9] Lastly, New York City Mayor de Blasio announced adding 9.2 miles of protected bicycle lanes to Brooklyn, Queens, and Manhattan. The city’s bike-sharing program, City Bike, reported a 67% increase in usage during March 2020 alone.[10]

New York’s mission to spend $1.7 billion on expanding bicycle lanes cited “addressing climate change, unclogging traffic, and promoting exercise” as its main goals.[11] With the surge in cycling rates, U.S. cities could learn from Copenhagen by focusing on safety and comfort. One way to prevent bike accidents is to designate separate, raised bicycle lanes to clearly delineate cyclists from cars. Good biking infrastructure can indeed reduce traffic and road congestion by allowing people to safely and freely pass one another in the bike lane.

Final thoughts:

In conclusion, increasing investments into smart bicycle infrastructure (separated from roads, clear line markings, room for passing, etc.) can increase people’s confidence in bike safety and increase our national cycling rates. Cities that decrease their commuter dependence on automobiles can also jointly address transportation emissions, citizen health, and equity concerns — while individuals can better enjoy their surroundings, exercise, and get some fresh air.

So to all my fellow classmates, strap on your helmet and let’s go for a ride!

Bonus tip:


[1] Mckenzie, Brian. “Who Drives to Work? Commuting by Automobile in the United States: 2013.” Aug. 2015.

[2] Peter S. Goodman, “The City That Cycles With the Young, the Old, the Busy and the Dead,” The New York Times, November 9, 2019, sec. World,

[3] “Preliminary US Greenhouse Gas Emissions Estimates for 2020,” Rhodium Group (blog), January 12, 2021,

[4] Brad Plumer, Nadja Popovich, and Blacki Migliozzi, “Electric Cars Are Coming. How Long Until They Rule the Road?,” The New York Times, March 10, 2021, sec. Climate,

[5] Ibid, Plumber, et al.

[6] CDC, “Obesity Is a Common, Serious, and Costly Disease,” Centers for Disease Control and Prevention, February 11, 2021,

[7] Eric A. Finkelstein et al., “Annual Medical Spending Attributable To Obesity: Payer- And Service-Specific Estimates,” Health Affairs 28, no. Supplement 1 (January 1, 2009): w822–31,

[8] The Canadian Press, “Walk, Bike or Take Transit to Work to Prevent Obesity,” CBC, March 18, 2016,

[9] “Electric Bicycles as a Tool for Essential Workers and Low-Income Populations,” People for Bikes, February 24, 2021,

[10]  “NYC Taking Advantage of Empty Streets to Add Bike Lanes,” Advocacy Advance, May 25, 2020,

[11] Goodman, Peter S. “The City That Cycles With the Young, the Old, the Busy and the Dead.”

6 thoughts on “Bike: for Your Earth, Health, and Community by Jessica Zhao

  1. I biked everywhere when I visited Copenhagen a couple of years ago and I remember loving the all the infrastructure supporting bicycle commuters (especially the little bike stoplights and turning lanes). I think it is a fantastic solution to many problems in cities, including, as you’ve mentioned, air quality, obesity rates, and traffic congestion. My initial concern with its feasibility in many cities, though, is cost-effectiveness: to establish bike lanes, you often have to take away road space. Justifying this shift (and the costs of implementation) almost requires evidence of high bike use, while high bike use almost requires safer infrastructure. In this chicken-or-the-egg scenario, it seems that we might have to wait for our biking infrastructure until bike popularity increases enough to put public pressure on city governments. You’ve pointed out that we’ve taken substantial steps in this direction during the pandemic, though, so hopefully it won’t be long before our cities are filled with bicycle commuters!
    I also had a brief question for you: do you have any sources that suggest what the emission impacts might be of a sizeable shift toward bicycle commuting? I’m curious to know how large a contributor in-city vehicle commuting is to our GHG emissions across the nation. Thanks!

    1. Thanks for your thoughtful response and question! I found a few studies comparing carbon emissions for different modes of transportation, mainly in Europe but applicable here as well.

      Study 1 from the European Cyclists Federation (ECF). (link:

      “When the complete life cycle of each mode is calculated, here’s how they stack up (results in grams of CO2 per passenger per kilometer traveled):

      Bicycle: 21 g
      Electric-assist bicycle: 22 g (e-bikes scored well due to larger range of standard bicycle and therefore greater chance to replace passenger car trips)
      Passenger car: 271 g (based on short trips similar to those a bicycle could make)
      Bus: 101 g”

      Another study published in Global Environmental Change analyzed city-based lifestyles. It found that “those who already cycled had 84% lower CO2 emissions from all daily travel than non-cyclists”, showing active mobility significantly decreased carbon footprints.

      I agree that cities must increase developments of safe infrastructure while we also raise the desire for individuals to change their commuting behavior. Hope this helped!

  2. Hi Jessica,

    Thanks for the post! I like the connections you made with my post, since I don’t think electric vehicles alone are the solution for the U.S.–bikes can play a vital role in our cities. I’ve personally seen changes as my city of New York tries to shift away from gas vehicles and becomes increasingly biker-friendly. A major intersection in Manhattan near my home decided to block off all vehicles except for city buses and bicycles starting last year. The street used to have 21,000 vehicles a day, so the contrast is stark and noticeable. When I’m walking around my neighborhood, the difference is very noticeable–not only due to less noise pollution, but also due to the increased presence of cyclists on the street. With only a few buses allowed to traverse 14th Street, it makes it safer and easier for cyclists to ride. While Manhattan does have bike lines along many streets, I believe implementing a car ban along other major intersections would only increase the number of people who feel comfortable using Citi Bike or riding their own bicycles. One reason why biking is so difficult even in dense American cities is that the cities were designed primarily for cars. If we could move away from that and make our streets more biker-friendly, more people will trade in their cars for bicycles.


    1. Hi Henry, thanks for sharing your insight from New York and the NYT article! I also noticed there were more bus and bike lanes when I visited this past year, but it seems like you’ve experienced a more profound impact living nearby. I actually rode a Citi Bike from North Williamsburg to the Brooklyn Bridge too, which ran right along the East River and felt surprisingly safe. Driving in Manhattan still makes me nervous, but biking might work!

  3. Having also grown up in a suburban area, I relied on biking to get around as a kid, and my town luckily had a 3-mile bike path that ran right by my house and looped around most of the area. After moving to a larger city some years ago, I have realized how much I took for granted how accessible my town was by bike and on foot. I was late to get my driver’s license solely because I didn’t really see a need for it, and after moving I realized I was completely isolated without a car and license. I also absolutely agree that this is a dilemma felt most strongly by the United States, as many European cities are just as large and urban and utilize public transportation, walking, and biking, far more than the average American (primarily because it is not an option in many cities here). Before reading this post, I was unaware of recent initiatives and investments in bicycle infrastructure across U.S. cities, especially amidst the COVID-19 pandemic, and I’m really glad that you highlighted this promising shift.

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