One common denominator of successful bike programs around the world -- from Paris to Barcelona to Guangzhou -- is that almost no one wears a helmet, and there is no pressure to do so.
In the United States the notion that bike helmets promote health and safety by preventing head injuries is taken as pretty near God's truth. Un-helmeted cyclists are regarded as irresponsible, like people who smoke. Cities are aggressive in helmet promotion.
But many European health experts have taken a very different view: Yes, there are studies that show that if you fall off a bicycle at a certain speed and hit your head, a helmet can reduce your risk of serious head injury. But such falls off bikes are rare -- exceedingly so in mature urban cycling systems.
On the other hand, many researchers say, if you force or pressure people to wear helmets, you discourage them from riding bicycles. That means more obesity, heart disease and diabetes. And -- Catch-22 -- a result is fewer ordinary cyclists on the road, which makes it harder to develop a safe bicycling network. The safest biking cities are places like Amsterdam and Copenhagen, where middle-aged commuters are mainstay riders and the fraction of adults in helmets is minuscule.
"Pushing helmets really kills cycling and bike-sharing in particular because it promotes a sense of danger that just isn't justified -- in fact, cycling has many health benefits," says Piet de Jong, a professor in the department of applied finance and actuarial studies at Macquarie University in Sydney. He studied the issue with mathematical modeling, and concludes that the benefits may outweigh the risks by 20 to 1.
He adds: "Statistically, if we wear helmets for cycling, maybe we should wear helmets when we climb ladders or get into a bath, because there are lots more injuries during those activities." The European Cyclists' Federation says that bicyclists in its domain have the same risk of serious injury as pedestrians per mile traveled.
Starting next year, two TBMs will build the tunnels, digging at a rate of about 40 feet per day far beneath the surface of the city. Prefabricated tunnel segments will be put in place as the TBMs advance, with a crew of about seven workers operating the machines and welding the segments together.
Each TBM consists of a rotating cutting wheel (the cutter head), a cylindrical steel shell (the shield) and a 300-foot train of tunnel-building contraptions (the tail). It takes about a year to construct this complex construction equipment.
SO GREAT! My high expectations were exceeded. I can say without hesitation that those of you who missed this show fucked up. The last time I saw them I was sitting on a carpeted floor in a hotel lobby with the lights on and it was still a great show, but this was just fantastic. You know that feel when you finally discovered The Knife but to see them you had to go to some despicable outdoor festival? This is your feel two years from now because you don't listen to me.