In short: Each New York cab journey is a single line, from pick-up to drop-off as the crow flies.
Description: This image is a simple geographic representation of all pick-up and drop-offs of each taxi journey in NYC at the beginning of 2015. Each journey is added to the image as a straight line between the two points and summed. The color-scale is designed to provide contrast while showing the movement as one interlinked object, removing the familiar geographic structures seen in the previous images. The only region that still retains its street-like appearance is an almost ghost-like Manhattan, which aids the viewer in identification and gives an overall frame of reference.
Point of interest: As well as the obvious hot-spots, this image shows us various step-off points for journeys in sparse areas before the sheer volume of journeys has washed out the data. A minor but very revealing journey is the hasty last-minute ride from the JFK Airport Holiday Inn to La Guardia Airport, the data unfortunately does not reveal the level of any associated swearing during such a trip.
Technical: 6 months of yellow cab trip data for (Jan-Jun 2015) available at https://nycopendata.socrata.com/. Image shows linear 2D image of all GPS Latitude and Longitude co-ordinates of taxi pick-ups and drop-offs for all journeys within limits of the image displayed as an as-the-crow-flies summation. The color channels are a combination of Log and Linear scales applied in different weightings when image equalization thresholds are crossed.