What is most fuel efficient SF<->South Bay commuting option?
During the first 25 years of my life, I sanely commuted less than one mile between work/school/home. Then, year 26 rolled around and I decided it would be fun to move 30 miles away from work. (What an exciting challenge!) For the past ~4 years, I’ve been commuting from San Francisco to Mountain View/Sunnyvale and been experimenting with many commuting options. Millions of workers do the San Francisco <-> Peninsula commute every day. I’ve tried many different combinations (walking, biking, scootering, train, bus, car). The three most popular options are car, bus, and train - Which of these methods of transit is the most fuel efficient?
After some rough ridership calculations, I found the bus and Caltrain are ~4x more efficient than cars.
Average car fuel efficiency: 25 miles / gallon / person
Average bus fuel efficiency: ~80–210 miles / gallon / person
Average Caltrain: ~90 miles / gallon / person
Given these numbers I’m particularly excited about the next steps for Caltrain electrification, which will see 75% of Caltrain’s diesel service replace with electric.
References:
Car EPA Automotive Trends Report (Section 1): https://www.epa.gov/automotive-trends/highlights-automotive-trends-report#Highlight4 *Assumption: Single occupant
Bus US Department of Energy Fuel Efficiency by Vehicle Type: https://afdc.energy.gov/data/10310
(4–7 m/g) * (20–30 people) = ~80–210 m / g / p
Caltrain 2017 Caltrain Yearly Report (page 15): http://www.caltrain.com/Assets/_Planning/Sustainability/Caltrain+Sustainability+Summary+Report.pdf
Caltrain uses 4.6 million gallons of fuel / year.
(~500 trains / week)(52 weeks / year)(50 miles SF -> San Jose) = 1,300,000 miles / year
(30 trains / week)(52 weeks / year)(30 miles San Jose → Gilroy) = 46,000 miles / year
(~1,350,000 miles / year) / (4,600,000 gallons / year) = (~0.3 miles / gallon)
(~0.3 miles / gallon) * (~300 people average on train) = ~90 miles / gallon
