What if time earning money for transportation was factored into your average speed?
I call this "True Average Speed".
Consider: You are broke in Los Angeles and need to get to New York. How fast can you earn the money to buy a bike and ride it there? How long would it take to save up for a car and drive there? Which option would get you to New York faster? (Transit advocates, don't spoil the answer).
Or maybe you own a care in a congested compact city. Would it be a better deal to buy an electric cargo bike and use transit and ride share instead?
The True Average Speed formula will show that the further and more frequently you travel, the higher the "true average speed" of a car can be. And for short urban trips, the relative true average speed of a bike versus a car can be eye-opening.
Ingredients to Calculate a True Average Speed
- The cost to operate a vehicle for a year. This may include car payments, gas, insurance, registration, accessories, maintenance– Everything. If the car is paid off, don’t forget to attribute some part of it’s cost to each year of it’s expected life span. In the United States in 2022, a reasonable estimate is $800/month.
- Your average hourly wage for the year (Take home pay, after taxes)
- Total distance traveled for the year
- Total time spent in the car for the year
True Average Speed Formula
Your true average speed is calculated by dividing your total distance traveled for the year by the total time spend on or in your vehicle.
Your "hours spent earning your vehicle per year" is the cost of the vehicle per year divided by the your hourly wage.
Your "Total vehicle hours/year" is the sum of the hours spent earning the vehicle, plus using the vehicle.
Finally, your true average speed found dividing your annual distance divided by your total vehicle hours.
Calculate your own true average vehicle speed
Try your own calculations here and share interesting results in the comments below!
Keep in mind that this formula only deals with direct personal time expenses. It does not factor in the health benefits that a mode of transportation provides or systemic or environmental costs.
To use the template you must make your own copy:
Start by opening the fie, Calculate True Average Speed.
If you are logged into your Google account and if Google Sheets is your go-to spreadsheet software, select File > Make a copy.
If you are not logged into your Google account, you can login and then make a copy. Or if you prefer another spreadsheet software, select File > Download as, and choose Excel or another format.
A version of this was first posted in September, 2006 as "Calculate Your True MPH" on bikes-as-transportation.com.
Update August 2023: The same concept might also be called "Thoreau Speed", as Henry David Thoreau described comparing walking versus rail travel in Walden in 1854. See Caleb Crain's What's your Thoreau Speed? In turn, Ivan Illich highlighted this in 1974 book Energy and Equity.