Friday, May 30, 2014

LaGuardia Airport Taxi Origin and Destinations, 2013

I've always been curious what the taxi travel patterns for LaGuardia Airport look like since it is the only practical method of travel to and from for many travelers.   Using the data from my previous post on processing all taxi trips for 2013, I did some analysis of just LGA taxi trips.

I think this side by side map viewer shows the patterns best.  Click on the map to open.

Of course there is significant activity near locations you would expect such as Penn Station and Grand Central Terminal.  The next level of features is dominated by large hotels.  If you zoom to lower Manhattan I added a number of hotel locations to highlight this pattern.

I would have liked to have also done a JFK comparison but most trips are to and from Manhattan and it is flat rate. This leads to the meters being started and stopped during the trip and not when the trip starts and finishes.  There are thousands of locations along the Van Wyck.

Passenger data for JFK and LGA, 2013

Taxi Trip totals for Airports, 2013

Time of Day, Day of Week Heatmap for LGA Drop-offs, 2013

Avg. number of drop-offs per hr

credit -

Thursday, May 8, 2014

NYPD Motor Vehicle Collisions

After a year of working with NYPD Collision data that was aggregated to the intersection by month, it was exciting to see this data release by individual collision with a date and time.

Congratulations and kudos to all that worked to make this happen!

This is also personally very satisfying.  I became involved in helping geocode the crash data that was at the time in pdf format as a direct result of this article.

The highlight was -

Council Member Jessica Lappin got into an animated discussion with Petito over traffic crash data. When Lappin asked why NYPD is releasing data in PDF form — and only after the council adopted legislation forcing the department to do so — Petito replied that the department is “concerned with the integrity of the data itself.” Petito said NYPD believes data released on a spreadsheet could be manipulated by people who want “to make a point of some sort.” An incredulous Lappin assured Petito that the public only wants to analyze the data to improve safety, not use it for “evil.”

I think everyone involved showed that while not every representation of the data is going to be perfect, providing this data in a publicly available usable format is valuable for everyone.

That said, some caution must be used in working with this new data.  Over 13% of the records do not contain coordinates, borough, or ZIPCode.

The large majority of the intersections missing coordinates are easily geocoded.  The caveat being that you need to make sure it isn't an intersection name that exists in more than one borough.

Here are the top intersections by count in the NYPD Motor Vehicle Collisions data that do not have coordinates.

From my previous work getting this data geocoded, I have a list of NYC intersections and their coordinates.  Would be great if the data could be augmented with this and made available -  

Street,street2,Zipcode,boro code,PolicePrecinct,Lon,Lat
1 AVENUE,39 STREET,11232,3,72,-74.01273692,40.65662545
1 AVENUE,40 STREET,11232,3,72,-74.01327021,40.65605997
1 AVENUE,44 STREET,11232,3,72,-74.01563035,40.6537815
1 AVENUE,47 STREET,11232,3,72,-74.01738143,40.65210968
1 AVENUE,48 STREET,11232,3,72,-74.01796511,40.65154416
1 AVENUE,53 STREET,11220,3,72,-74.02087613,40.64874399
1 AVENUE,53 STREET,11232,3,72,-74.02087613,40.64874399
1 AVENUE,54 STREET,11220,3,72,-74.02145974,40.6481812
1 AVENUE,56 STREET,11220,3,72,-74.02262334,40.64706385
1 AVENUE,ALLEN STREET,10003,1,9,-73.98863937,40.72293374

Otherwise the data looks pretty good and consistent for the dates available. I'm very curious to see if it actually updates every day.  So far it didn't today. Still, awesome to see this data released this way.

The spikes seem to correlate with snow storms.  The 'down' spikes seem to be holidays.

Lastly, the older NYPD data documents the vehicles involved.  This allows for some interesting insights on some specific crashes.  I was very surprised at how many fire trucks and ambulances are involved in collisions.