You’re racing down Main Mall on your bike, weaving in and out of the hordes of students, trying to make it to your next class on time. You might want to rethink how fast you ride.
Dr. Alex Bigazzi is a professor in UBC’s civil engineering and the school of community and regional planning, whose new study is particularly interesting for bikers because it looks at how they can reduce their risk of air pollution inhalation.
The paper used different models for cyclists and pedestrians to determine the sweet spot of maximizing your speed while minimizing breathing rate. This optimal trade-off is what Bigazzi called “the minimum dose speed” (MDS) which gives you the least total air pollution inhalation over a trip.
The MDS varies between age and sex, and it is pretty similar to normal riding speeds. For female cyclists under 20, the speed that minimizes their pollution inhalation is 12 km/h. In contrast, male cyclists under 20 should ideally bike at 13.3 km/h. For cyclists aged 20 to 60, the optimum MDS is 13 km/h for women and 15 km/h for men. Additionally, Bigazzi’s study found that in order to minimize the volume of pollution inhaled, pedestrians under the age of 20 should aim to walk at around 3 km/h, while older pedestrians should walk at around 4 km/h which is a little slower than average walking speeds.
If you don’t think it’s possible to regulate your riding speed, you probably shouldn’t worry too much in a relatively clean city like Vancouver.
“If you’re on the seawall, it’s pretty clean. I wouldn’t worry about it so much. But if you’re biking along fourth avenue or the downtown core, it’s something you may want to think about more,” said Bigazzi.
If you expect to go through a zone with high pollution levels — such as a heavy transit road, construction zones or industrial areas — you may want to moderate your speed more.
“If you are going to get out there and jog or sport cycle, then it is particularly important to be away from high pollution areas, as your breathing intake is particularly large for high- intensity sports,” said Bigazzi.