Linear: Study 1


In short: Each New York cab journey is a horizontal line; moving from bottom to top is the length of the journey and the width of the line is the fare (plus tip) over a standard rate.  Green indicates night and purple day.

Description: The other images on this data-set were preoccupied with the journey each passenger was taking. An overlooked group are the cab drivers themselves who are making a living. Aside from what we’ve already looked at, what else would the cab drivers be interested to see? This plot shows how the length of the journey relates to the money earned (fare plus tip), the further up the image the longer the journey – in this case a maximum of 1 hour, but the scale is irrelevant as an experienced driver would naturally know what is a “long” or “short” fare. The width of the image shows the money earned above a standard $30/hr plus $2 surcharge. Again, the scale is irrelevant as the idea would be to aim for an approximate time where the dark region is at its widest (with green being day, purple being night). A glance should allow a cab driver to estimate about a 20-30min fare is the most lucrative during the day, and slightly less at about 15 minutes in the evening. Obviously turning down fares based on this estimate would overall not be a good idea, but it addresses an aspect in the data that a different group would find more relevant. In terms of what is being shown, the other images have attempted to show multi-dimensional data within a two-dimensional space. Here the data is much more one-dimensional and is being applied to a two-dimensional space. (Interestingly, it also results in a very different object that is perhaps suggestive of a one-dimensional approach to another much more multi-dimensional issue, but it is perhaps best left to the viewer to see this…)

Point of interest: There are steps in the image that relate to a standard tip of a round amount being applied, whatever the journey time. These steps are angled inwards as the $30/hr model is subtracted. It is interesting that there are two large steps at tip amounts of $50 and $60, and then many smaller ones as the amounts are rounded up to the nearest $1. There is a faint indication of a $20 tip for shorter journeys but no indication of other amounts.

Technical: 6 months of yellow cab trip data for (Jan-Jun 2015) available at The data used are the time the journey takes and the fare (+tip) collected. Obviously the longer the journey the larger the fare, this component was removed as an estimate from the data of 30 dollars per hour, with a 2 dollar standard surcharge. The vertical direction is the time (up to 1 hour) and the horizontal width of the image relates to the fare plus tip collected (up to 100 dollars) above the linear component as a cumulative histogram of all journeys. An offset normalization was applied to bring out the larger sums collected by the driver. This data was split to be within 6 hours of midday or not, and the two plots added with the red/blue channels signifying daytime, the green signifying nighttime (i.e. to put it simply green is predominantly daytime trips, purple predominantly nighttime and black is no difference day or night).


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