Bicycling Counts: Official Counts
The Numbers Behind Bicycling Counts:
Bicycling Counts is based on real Twin Cities data. The interactive infographic tallies financial savings to the individual and society (in terms of healthcare and clean air) as well as gasoline savings. We identified and linked together available data and studies to make the calculations behind the project. The installation's aim is to provide an estimated impact for each passing cyclist that it "counts". According to the latest Travel Behavior Inventory study, 2.3 miles is the average (7-county) Metro area bike trip. We tailored the project's calculations to this distance. The average bike time in the Metro area is 16.91 minutes.
Savings to Society:
A recent study highlights the air-quality and excercise-related health benefits from reduced car travel in the Midwest. “Making 50% of short trips [≤ 8 km = 4.97mi.] by bicycle would yield savings of approximately $3.8 billion/year from avoided mortality and reduced health care costs (95% CI: $2.7 billion, $5.0 billion]. We estimate that the combined benefits of improved air quality and physical fitness would exceed $8 billion/year [Across the study region of approximately 31.3 million people and 37,000 total square miles].” This study states that each urban bike trip in Minneapolis saves $9.77 Because everything is based on estimates, we rounded this to the nearest whole dollar: $10.
Individual Financial Savings:
According to this study “A good bicycle with accessories typically costs $500-1,000, or $50-100 annually over a ten-year operating life, plus $50-200 annually for maintenance if ridden 2,000 annual miles, averaging 5-15¢ per mile.” We averaged this cost-per-mile to $.10. According to the AAA's 2010 Transportation Statistics Annual Report, the 2009 average cost of owning and operating a vehicle was $.57 per mile. At a $.47 savings per mile, the average 2.3 mile Twin Cities bike trip saves $1.08. Because a lot of this calculation is averaged, we rounded this number down to $1.
The average miles per gallon of gas of US cars is 23.8 mpg. We divided that figure by the average metro bike trip (2.3 miles) and found that, every 10 and 1/3 cyclists that pass save a gallon of gas. U.S. refineries produce about 19 gallons of motor gasoline from one barrel (42 gallons) of crude oil. So 196 cyclists on an average metro trip, together save approximately a barrel of crude oil.
For more information about Bicycling Counts, read the project background and an interview with visual storyteller Arlene Birt.
Bicycling Counts: Interview with Visual Storyteller Arlene Birt
Bicycling Counts: Calculating the Impact of Minneapolis Cyclists