About the NotSpot℠ Index



What's a NotSpot?

A NotSpot is a New York City Citi Bike station that is empty or full, rendering them useless to people who want to get or return a bike. Practically speaking, 98% of NotSpots are empty stations.


The NotSpot℠ Index



0-19 NotSpots

20-33 NotSpots

34-44 NotSpots

45 and above



How the index came about

Since Day 1 on this blog (January 5, 2014) we struggled to come up with an easily understood way to explain the status of the system, hour by hour, day by day.  We started reporting hourly counts of full/empty stations to selected NYC media outlets. But there was no context for the raw number.


On Feb. 25, 2014, we caught the attention of the NY Times metro blog, NYToday,  when we reported that 60 stations were empty or full. As The Times pointed out, 60 downed stations is about 20 percent of the system.


So if 20% catches the media's attention, thats got to be in the “red zone," right?. And if it's red when roughly 20 percent of the system is out to lunch, then 15% would be in the yellow zone, right? And 10%, green. And 5%, a heavenly blue, because with those low numbers we would have died and gone there.


How we get to the  weekly  NotSpot number

We conduct surveys weekdays on the half-hour, 8:30 am to 5:30 pm, recording data provided by Oliver O’Brien at the Center for Advanced Spatial Analysis. The number for the week is the average across the five days.

We filter out hours or days when it rains, snows, the wind is above 15 mph or the temperature is below 20F. Also filtered out are holidays and days when a heat emergency is declared.

2 comments:

  1. Great initiative. Would be even more awesome if there was a way to track the percentage of time that a given station is in 'NotSpot' mode so that people would learn to avoid the really problematic locations. In fact, maintaining network coverage with variable demand conditions is an extremely complex network 'optimization' problem!

    Presumably there is some strong 'directionality' of flows during peak periods (ie stations emptying in certain areas and filling in others). Montreal has gone so far as to set up a few 'depot' stations where there are no limits on return capacity. After (or during) the morning rush the bikes are then redistributed back onto the network.

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