When I lived in London, I used to regularly jog along the Thames at lunch time. My co-workers often used to tell me that they wouldn’t do it because I was breathing in all those fumes from vehicles. They felt the air was much healthier in a car or bus. I never cycled in London (in the late 90s noone did except bicycle couriers) but I am sure I would have heard the same arguments against cycling. And in fact this BBC article makes exactly that claim.
However, an experiment in London has shown once again that “common sense” assumptions are often wrong and the truth is counterintuitive.
The experiment was carried out to compare the amount of pollution encountered by one person on a bicycle, one in a car, one walking and one on a bus. The experiment was repeated on both a busy road and a quieter route.
The result was that the people walking and cycling were shown to be exposed to considerably lower levels of pollution. In contrast, the persion driving a car was exposed to the most pollution with the bus passenger not far behind. Not only that, the people on bicycles took almost half the time the person in the car took to make the same journey.
Interestingly, the person who cycled on the quieter route was exposed to 4 times less pollution than the person cycling on busier roads. While I would have expected the levels to be lower, 4 times is a substantial difference. It does perhaps suggest one factor in favour of projects like the Dominion Road parallel route – though there is a good argument this will be offset by fewer people using such a circuitous and less connected route.
As with so many transport issues, the obvious and generally accepted answer is not necessarily the correct one. Just another reason why bicycles are the ideal solution for short, urban journeys.