Though they are not first to do this, Dutch researchers have calculated the effects of different travel mode choices on life expectancy. The study is called Do the Health Benefits of Cycling Outweigh the Risks? The researchers based their calculations on an examination of traffic accidents, exercise and air pollution.
Good enough, but excuse me if I’m about to restate the obvious. There are also a quality-of-life issues, and they aren’t the same for everyone — far from it.
Time spent traveling and earning income to pay for the travel can add up to many years of a person’s life. This time could be enjoyable, or a dull chore, or a drudge. The cost may be trivial to one person, but a major burden to another.
The ability to work, read or converse is a time saver with public transportation or carpooling; less so for walking, even less for bicycling; not for driving alone unless perhaps listening to an audiobook or talking on a cell phone — well, let’s not go there. Aerobic exercise when bicycling or walking is a time saver for people who value the exercise, and it also increases life expectancy. Need I say, physical fitness also increases quality of life.
Time may be spent waiting for the bus or train to arrive, waiting in a traffic jam, waiting for traffic signals, hunting for a parking space, walking from and to that parking space.
Owning and operating a private car is expensive to the individual; public transportation, generally less so; bicycling, even less and walking only wears out shoes occasionally. However, the infrastructure costs of all of these modes of travel are largely subsidized from public funds.
At this point, we get into issues of the individual vs. society. Examples: a private motor vehicle is a major time saver unless there are too many of them, causing traffic congestion, air pollution, global warning. Then the interests of society at large suggest investment in other modes, while the interest of individuals still favors the private car — for other reasons as well, particularly weather protection, convenience in transporting passengers and cargo, and the low marginal cost of each mile of travel relative to the fixed cost of car ownership.
Which leaves us more or less the situation we are in now. Investment in public transportation as well as innovative solutions such as convenient car and bicycle rental can help shift the balance, but worldwide, the private car continues its upsurge,.
The Dutch study you mentioned has cycling appearing worse off [due to air pollution and traffic dangers] than it should for two reasons:
1) Comparison only with the private car. Considering particles, a newish car with its effective filters is the best choice, but cycling and walking come second. Buses with their frequently-opening doors are particle traps. Underground stations are particle vacuums. There was a recent study in Helsinki about this.
I’d also like to cast doubt on vehicle choice as a particle-avoidance strategy. Considering that urban-dwellers spend most of their time indoors, I bet it would be most cost effective to invest to ventilation/filtering systems of homes and offices and choose the traffic mode that’s most suitable for the trip.
2) Comparison with bad cycling practice. Other than freak accidents, getting to the right side of right turning HGVs [heavy goods vehicles: big trucks] and buses is about the only way to get killed on a bicycle in Euro towns with slowish speeds. Everybody reading this can avoid most Euro-town fatalities by learning the “Street Smarts” linked in the top bar.