This article from the New York Times about grilock in New York is from two nights ago, but I think it’s worth a glance. The article is a great look at how slowly cars move. I especially like the line, “Weekday traffic in the district moved at an average of 9.5 miles per hour — about the speed of a farmyard chicken at full gallop.”
This goes to show how we often misperceive reality regardless of the underlying data. I know there have been plenty of times that I felt I made much faster progress during midday traffic, but the numbers don’t lie.
I wonder if they account for the different driving patterns between taxis and private cars and if that would make a difference. I wish the Times had posted a link to the original study so I could see the methods they used. I would guess they use spatial statistics that can track autocorrelation in time and space and there is a lot of power in those kind of tools.
Jared Lander is the Chief Data Scientist of Lander Analytics a New York data science firm, Adjunct Professor at Columbia University, Organizer of the New York Open Statistical Programming meetup and the New York and Washington DC R Conferences and author of R for Everyone.