Friday, March 7, 2014

Introducing the NotSpot Index

Thursday's empty station numbers at first left us pleased but befuddled. For the second week in a row, the Thursday empty station numbers are way, way down from Mon, Tue and Wed.

But we're left trying to explain, in bumbling ways, what these changes in the system's performance mean. How good was Thursday? Or how bad were Mon, Tue and Wed?

Then it came to us: If 60 empties captures the attention of NYToday, that’s gotta be in the “red zone," right?. If red is when roughly 20 percent of the system is out to lunch, then 15% would be in the yellow zone, right again? And 10%, green. And 5%, a heavenly blue because with those low numbers we would have died and gone there.

So, introducing the NotSpot Index

0-16 NotSpots
17-33 NotSpots
34-50 NotSpots
51 and above

How did we get to this number?

It is the rolling average of the number of NotSpots we find during a survey of the data provided by Oliver O’Brien at the Center for Advanced Spatial Analysis.

We conduct multiple surveys on weekdays starting about our third cup of coffee and ending about the time we post our daily summary, and tweet, and fb and…

What’s a NotSpot?

A NotSpot is a station that is either empty or filled at the time we conduct a survey.
And now returning to our regular programming...

Thursday’s King of All NotSpots

Tribeca’s Harrison St & Hudson St station. At 20 bikeless hours, this one’s more like a Duke.

Available bikes
The count stayed above 4,000 all day. That seems to be a good thing, too.

Bikes available at 5:30 pm Thursday: 4148
Bikes available at around the same time yesterday: 3948
Bikes available at around the same time a week ago: 4377

The 5:30 (or so) pm NotSpot survey

NotSpots at 5:30 pm Thursday: 21

NotSpots at at around the same time yesterday: 25
NotSpots at at around the same time a week ago: 17

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