Commuting Costs Spreadsheet

In my last post on Gas Prices and Commuting I confessed that I whipped up a spreadsheet to model the commuting costs of several options. It started with a basic question of "I wonder at what gas price it will make financial sense to take the train instead of the motorcycle?"

Note that this was just financial sense! Which makes this somewhat of an academic exercise because there are other factors to consider in the question of commuting options. How about: commute times, flexibility, carbon footprint, productivity.

I attempted to include in the model:

• fuel costs ($/gallon)
• train/bus fares (using 10 ride CalTrain tickets)
• parking (daily parking costs)
• oil changes (every 3000 mi for motorcycle, 5000 mi for car)
• tire cost (ballpark cost of tires per mile)
• pre-tax treatment for commuting benefits

The pre-tax treatment is pretty important. Parking and mass transit costs can be paid from the pre-tax withdrawals from my paycheck - using a 34% tax rate means that $10 paid from pretax money is only equal to $6.60 of after tax money.

Here is a shot of the spreadsheet table. The final cost is a round trip total. the blue shaded items are the ones that can be paid from the pre-tax account. Here is a view only version of the sheet on Google Docs. If you want to know more just let me know via the comments.

Note: At the time of this post, our gas price is $4.599/gallon. To answer my original question, I just kept increasing the $/gal until the total amount for the train was less than the motorcycle amount. This happened at about $6.70/gal.

After comparing the motorcycle to taking CalTrain to SF, I added a few other commute options which aren't really options until we buy a second car (which we'll do soon before Baby G arrives).

What can you do with a similar sheet? Compare your commuting options, compare the costs of a commute with two different vehicles you are considering buying, calculate your total commute costs over a period of time.

Embrace the spreadsheet! It's your friend!