How Can We Cut Our Energy Use for Commuting?

How can we cut our energy use for commuting? What methods are working for you? What methods make most sense in our current credit environment? This is mostly an open thread, to give people an opportunity to talk about what is and isn't working for them. If the economy is sputtering, peak oil is around the corner, and hurricane related shortages are becoming more common, these methods are going to more and more important in the days ahead.

Some ideas that have been suggested include:

1. More work at home plans, possibly a few days a week.
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2. Using a four day (or three day) work week. (See The Four Day Work Week: Sixteen Reasons Why This Might Be an Idea Whose Time Has Come.)

3. Moving closer to work.

4. Using public transit.

5. Using car pools or van pools.

6. Using a more efficient car.

7. Using a motorcycle or moped instead of a car.

8. Using a bicycle.

Of these, work at home (1), four day work week (2), and car pools (5) seem to be the lowest cost alternatives, since they do not require the addition of any other infrastructure, and do not require moving. Using a bicycle (8) is also inexpensive, and gives a person exercise as well. More use of public transit (4) requires infrastructure investment and a longer time frame. In a credit constrained environment, they may not be as feasible.