Benefits of Commuting by Bike
I wanted to share this excellent LinkedIn post from U. Bryn Grunwald calculating the time spent, money spent, excercise and emissions of riding a bike to commute rather than driving. I love this kind of thinking!
Here’s Bryn’s post’s text:
Today, I had something to do on the other side of town, about 5.6 miles away from my house on my bike. Like I usually do, I decided to bike there. But I wanted to see how this 11.1 mile round trip would stack up compared to driving it.
1. Total distance. I could hit some short cuts and had a relatively direct path to the location. Biking, it was 5.55 miles one way. Driving would have required a more circuitous path, with Maps suggesting one that would be 5.9 miles. The rest of my calculations for time and emissions are using the 11.1 miles I ended up doing on my bike for comparison, rather than the 11.8 miles I would have driven (0.7 miles more!).
2. Time spent. I left my house ~8.10AM, which is about when traffic starts building up in Boulder. I checked the time estimate to my destination on Maps if I were driving it, and it was estimating 15 minutes with current traffic conditions. I timed myself biking there, and I got to my destination in 21 minutes – six minutes slower than driving. However, I spent much less time stopped. I had to wait at only two stoplights on my bike route (Boulder has some great pathways and underpasses), whereas I could have hit 9 stoplights on the driving route Maps suggested. The National Association of City Transportation Officials says that the average time spent waiting at a red light is 75 seconds, so getting stopped at any of these lights would have added to my time. This also does not include time to find parking and walk over, whereas with my bike, I just took it inside with me.
3. Money spent. My 2010 Camry gets about 22 mpg in the city. Gas right now is ~$2.90/gallon. Driving the car also contributes to the overall maintenance costs, with the DOE estimating 10 cents/mile. So the cost of driving the 11.1 miles would have been ~$2.58. With the efficiency of my e-bike and the cost of electricity, I spent just under 3 cents to bike. Pretty significant savings.
4. Exercise. I like to bike on eco-mode, which mostly offsets the weight of the bike, and then I use the throttle to get going from a stop. I’ll count this as light exercise. In total, I spent roughly 43 minutes biking out and back. Using Cronometer, it estimates my total calorie burn at 261 calories – roughly the same amount of calories as three boiled eggs. The CDC recommends an adult get 150 minutes of physical activity per week, so I am already 29% of the way there.
5. Emissions. Driving there and back would have put out 9.9 lbs (4.5 kg) of CO2e from the roughly half gallon of gas I would have used. Biking took ~0.2 kWh. With Colorado’s current energy mix, the emissions from biking add up to about 0.14lb (0.06kg) CO2 – 1.4% of the emissions I would have produced while driving. It would also produce much less PM2.5, NOx, SOx, and VOCs, which has significant health implications.
More abstractly, I think I had more fun biking than I would have had driving. Some things are easy to compare, but the abstract joy matters too.