What Kind Of Commute Makes People Happy?

Last week, I saw something on Twitter I had already seen several times: a link to studies suggesting that people are happier when they can walk to work than when they spend a long time driving to work. This claim strikes me as only slightly less obvious than the claim that water is wet. But at the same time, it raises more questions than it answers. For example:

*Is commuting-related unhappiness limited to driving, or is the long-distance commuter equally dissatisfied whether she bikes, drives, takes a bus, or takes a train? Or to put it another way, does the sheer length of commuting reduce well-being, or is mode choice also an important factor? For example, if a commuter's choice is between a 20 minute drive and a 40 minute subway ride, which is more demoralizing? One British study suggests drivers are as happy or happier than transit users when commuting time is equal; another study disagrees.

*The "short walk/long drive" dichotomy presupposes that work is in a downtown or other walkable neighborhood, while the long drive is from the outer edges of suburbia. But most Americans (including me) work in suburbs. If a commuter's job is in a suburban office park, is he happier living close to the office park, or should he prefer a long ride from a more walkable neighborhood?

*Given that, other things being equal, a short walk is better than a long drive, how should a commuter weigh that factor against other factors? For example, the rent for my current apartment in Manhattan is comparable to the rent for a two-bedroom apartment in Queens, or a three-bedroom house in Suffolk County. As a single person, the extra space is useless to me. But if I had a spouse and a child or two, would the benefits of the extra space outweigh whatever unhappiness I suffered from my commute?

I don't know the answers to any of these questions; I only claim that further research is worthwhile.