** Update (1/28/17): This app is no longer available in the app store.

In November I competed at Hack Princeton with my teammates Hill and Tommy. We developed an iPhone application that provides users a map of the best nearby intersections to hail a cab in Manhattan. It took home 2nd place in the software track and won the ‘Best Use of MongoDB’ award. Over the holiday break I cleaned up the UI and submitted it to the app store and now it’s live - Hail Yeah!

Below is the video of me pitching Hail Yeah at the hackathon.

How does it work?

Our app uses a publicly available dataset describing the ~200 million taxi trips taken in and around Manhattan in 2013 [Download link]. Thanks to the Freedom of Information Act, the NYC government and related authorities provided details of every taxi trip, including where it began, where it ended, when it took place, and even how much the rider tipped.

First we bucketed the start location of these trips to their nearest intersections. Then for each intersection we broke down the trip totals by the day of the week and the time of day.

When a user sets a location in our app, we use the historical information described above to calculate the frequency of taxi pickups for all intersections within a quarter mile radius of the user’s location given the current day of the week and time of day.

The resulting information is presented as an intersection heat map, with a color scale at the top for reference.

Photo

The app was written in Objective C, it uses google maps, and our intersection database is hosted on Parse.