The American Public Transportation Association (APTA) has a new study that shows how much money a household could save by switching to public transit. For example, the APTA study estimates that if a Seattle household traded in one car and used transit they would save about $10,447 per year.
The study conveniently explains the methodology used to estimate their figures:
APTA then compares the average monthly transit fare to the average costof driving. The cost of driving is calculated using the 2009 AAAaverage cost of driving formula. AAA cost of driving formula is basedon variable costs and fixed costs. The variable costs include the costof gas, maintenance and tires. The fixed costs include insurance,license registration, depreciation and finance charges. The comparisonalso uses the average mileage of a mid-size auto at 23.4 miles pergallon and the price for self-serve regular unleaded as recorded by AAAon April 8 at $2.047 per gallon. The analysis also assumes that aperson will drive an average of 15,000 miles per year. The savingsassume a household gives up one car.
There is one variable however, the study failed to account for: the value of time. One of the most significant tradeoffs with switching from driving to using public transit is the extra time involved. For example, commuting door-to-door from south King County to downtown Seattle takes about 1 hour in a motor vehcile. (obviously, this estimate can change drastically depending on where you live. Switching to public transit would take 2 hours to make the same trip, door-to-door.
Everyone has their own opinion on how much an hour is worth to them. If I valuled my time at $35 per hour, and added two extra hours of commute time, the cost of moving to public transit would be about $19,600 per year. This means it would cost me about $9,123 per year to switch from driving to public transit.
The following table shows how much two extra hours of commute time per day (annualized) would mean to you, depeding o! n your personal value of time:
Value of 1 hour | Extra cost per day from using Transit | Annual cost, based on 260 work days per year |
| $15 | $30 | $7,800 |
| $20 | $40 | $10,400 |
| $35 | $70 | $19,600 |
| $50 | $100 | $28,000 |
| $100 | $200 | $56,000 |
Assuming your commute time would increase two hours per day, you would have to value your time at less than $20 per hour to make the switch from driving to transit make sense.
