Lydia DePillis, who often writes on bicycling matters for the Washington Post, had a column on Friday (yes, April Fool's Day) as part of the Post's "Five Myths..." series. It was more good than bad, but some of the bad is glaring.
First of all, the myths themselves were a little weak. No one really says that bike share will make roads less safe, for example, at least not anymore. It would have been nice if she had found actual claims from recent, main stream publications (I'm sure the Post has some thanks to Courtland Milloy) and then shot those down.
1. Mandating helmet use is the best way to keep riders safe. - People do advocate for this at times, but I feel like it's more or a larger myth which is that "the most important thing a cyclist can do for safety is wear a helmet." I think helmets, on average, probably improve survivability of crashes and mitigate certain types of head injuries, but I'd say it's less important than a bike in good working order, a sober and confident cyclist and a good pair of bike lights (if riding when those are needed). Still, this myth is in the same vein. And she largely makes the same point, that there are better ways and that helmet laws are likely counter-productive.
Unfortunately, she kicks it often with the since publication withdrawn claim that "Studies show [that helmets] reduce the risk of cyclist head injury by 85 percent" which I found surprising, but it is a widely repeated claim so I'll let it slide (though she should correct this).
3. If more people rode bikes, there’d be noticeably less traffic and pollution. I guess she's trying to be balanced here by knocking down a myth of cycling evangelists, but it's not a myth. If more people rode bikes there would be less traffic and pollution - in proper relation to the number "more" we get. No one says that doubling bicyclists will end congestion and pollution, they say that to the extent that you transition rides from cars (and to a lesser extent transit in some case) you see a reduction in congestion and pollution.
Sure, if everyone gave up their cars tomorrow, the health of our cities and our climate would improve. But this is wishful thinking. Just 1 percent of Americans regularly commute by bicycle. Even if that number doubled, cycling wouldn’t significantly cut smog and congestion.
Actually, it probably would. Both congestion and smog are concentrated in the same areas - cities. Exactly the places where cycling is most prevalent. If bike commuting doubled, DC would go from 3.9% to 7.8%. I'm certain an overnight change like that would be noticeable. A place like Berkeley would get to nearly 20% and San Francisco (#7 in air quality) to 8.8%. I think that would result in a measurable reduction in air pollution.
Even the posts she linked to make this point. The Streetsblog post is about an actual study.
In a scenario where 14 percent of travel in the world’s cities is by bike or e-bike in 2050, carbon emissions from urban transportation would be 11 percent lower than a scenario where efforts to promote sustainable transportation sidestep bicycling.
That's doable. That's noticeable.
On congestion, she misreads the research. She writes that
Studies have shown that congestion increases in cities where there are more bike riders but no new bike lanes.
But that isn't what the study shows. It shows that on some roads, if bicycle use goes up, travel times goes up too. Mostly those are the uphill segments of narrow roads where drivers can't pass cyclists - and it's worse if there are buses too. It does not translate citywide and they don't even study what happens to the whole city. Other studies meanwhile, show that - on average - a bicycle causes about 28% as much congestion as a car, and that goes down as there are more bike facilities added. But 28% is the maximum.
This was by far the worst myth on the list. It was a complete strawman, and not even supported by her own facts.
Anyway, those are my thoughts.