Not web traffic, or human trafffic. Car traffic! I was in the middle of reading the New Yorker article about traffic in Moscow (it's bad) when I read this about the effects of public transit and congestion. My Russian correspondent says it takes as long to get from Moscow to her house in a suburb 70 km away as it does to fly from Tel Aviv to Moscow (4 hours. 4 hours!). The point of the article in the link is that public transportation is great, but not because it decreases congestion. This would make sense if the actual number served by public transportation were very small compared to the number of total cars on the road - but I am not sure if this is true. BART, the Bay Areas subway/ metro system serves about the same number of people a weekday as use the Bay Bridge 330,000 and 300,000. Say about a third of the people on Bart are making the East Bay to SF commute, and half the people on the Bay Bridge are driving towards SF, about 110,00 people a day use Bart to commute to SF, and 150,000 a day use the Bay Bridge. Obviously my percentages are invented, but it is hard to see how increasing public transit ridership by, say 20% wouldn't decrease traffic.
Perhaps the more interesting point of the article is that public transportation is important because it increases efficiency at any given level of traffic by allowing more people to enter the labor market (or get better jobs).
