bicycling

It's Bike to Work Day! Here in DC 14,000 people signed up to participate, and volunteers staffed 72 pit stops to offer refreshments and prizes to cyclists. Between 2006 and 2011, the number of DC residents who commute by bike jumped from 5,667 to 9,669 (accounting for 2% of commuters in 2006 and 3.15% in 2011). Figures from other cities are available on this map from GOVERNING. It's not surprising that more DC commuters are biking, because over the past few years the city has made substantial investments in bicycling infrastructure. Our Capital Bikeshare system keeps expanding, and our…
The New York Times has a terrific graphic that plots the number of auto fatalities per 100,000 people and the vehicle miles driven per capita from 1950 to 2011. Overall, we're driving far more vehicle-miles per capita and seeing far fewer auto deaths than we were six decades ago, but this hasn't happened in a linear fashion. Rather, as Hannah Fairfield explains, change occurs unevenly: Plotting the two most important variables against each other — miles traveled versus deaths per 100,000 population — yields a pattern that looks like a plateau followed by a steep drop. It evokes the theory of…
Bicycling has been in the news a lot this week. E&E News reports that China is trying to get people back onto bicycles in an attempt to address traffic problems. The city of Zhongshan has launched a bike-sharing system with 4,000 bikes; Hangzhou and Shanghai have systems with 50,000 and 19,000 bikes, respectively. Reporter Coco Liu contrasts these figures to the US's largest bike-sharing program: DC's, with 1,100 bikes. (Read my earlier post on Capital Bikeshare here.) Even with such relatively large systems, though, demand can quickly outstrip supply, as when a train full of homeward-…
I ride my bike and mostly the wind makes me unhappy. On a very few days the wind is with me on the way to work and then changes so that it is with me again. But most days the wind is fairly constant. So, if the wind is constant then shouldn't everything even out? (Even Stephen). Assumptions: Let me start with the assumption that I (a mere mortal) can output at a constant power (but not 57,000 Watts like some people). I will also assume an air resistance force that is proportional to the square of the relative air speed. Here is a diagram. A couple of quick things to point out. First,…