The Most Dangerous Day in NYC

Based on Auto Collision Injuries to Pedestrians

It’s an understatement to call New York a commuter city. But is it a safe walking city? Are the cars afraid to hit pedestrians or are the pedestrians afraid of getting hit by cars? Either situation results in pedestrian injuries. I believe we can reduce pedestrian injuries with open data and craft more efficient ways to allocate funding for public safety.

Utilizing records of pedestrian collisions from NYC’s Open Data Portal, I have determined the most dangerous day on record for pedestrians in the hope of preventing that day from ever reoccurring.

The Most Dangerous Month

Number of collisions per month (Jan 2013 — Feb 2017)

Reproduce the numbers

The beginning of the year is key. Across all five boroughs, January recorded the highest number of traffic collisions leading to injuries for pedestrians regardless of time and place. Whether it was due to going hard with New Years’ Eve festivities, returning to school after winter vacation, or coincided with the shortest days of the year, January marks the most dangerous month for pedestrians.

Over half of the top-ten causes of collisions that led to pedestrian injuries can be prevented. Overwhelmingly, driver distraction and failure to yield the right-of-way resulted in the most collisions. Hard to control circumstances such as window glare, distracting passengers, or slippery pavements are minor causes.

Contributing Factors for Collisions (Jan 2013 — Feb 2017)

Reproduce the numbers

How did NYC respond to the most dangerous month?

This past November, the Dusk & Darkness Safety Initiative had NYPD the on alert for moving violations, which resulted in the following:

  • 12,151 summonses for disobeying a traffic sign
  • 5,253 summonses for improper turn
  • 4,880 summonses for illegal cell phone use
  • 4,268 summonses for failure to yield to pedestrians
  • 3,942 summonses for failure to obey red light
  • 3,893 summonses for failure to wear seat belts
  • 3,818 summonses for speeding
  • 3,066 summonses for texting

Next, the following months after the Dusk & Darkness Safety Initiative and its success are inferred below.

Historical Trends of Recent Years

(If you’re having trouble with the labels, you can check out the interactive version of the chart here.)


From the chart above, the beginning of the year is seen to have upswings in pedestrian injuries. The number of collisions rose during the Autumn months before peaking in January. That’s because this period coincides with the lowest amount of daylight hours that accelerates with the end of daylight savings. The regular work commute also contributes to the rise in collisions during this period. Prime traveling time occurs in darkness, as rush hour moves from occurring in daylight hours to after sunset. Additionally, the holiday season can bring out prime conditions for collisions.

Reproduce the numbers

2016 notably stood out for having the highest number of collisions than the year prior. An interesting point about 2016 is the peak from July’s trench (one of the lowest points) and August’s ascent. Regarding to pedestrian injuries, it was the largest month-to-month increase from the data. Moreover, the high point precedes the 2017 January upswing and the most dangerous day in NYC.

The Most Dangerous Day

On January 23, 2017, a record 228 pedestrians were injured from car collisions. The map below shows where pedestrian injuries took place during the day. When you hover over the collisions, you can find out details such as time of day, contributing factor, and location.

Mapping NYC on January 23, 2017

The injuries were dispersed across multiple regions instead of a few key areas. The date in question comes after the most dangerous year in recent history, in the most dangerous month, so therefore it seems like a logical time for such an outlier to occur.

Contributing factors for the MOST DANGEROUS DAY

Reproduce the numbers

All things considered, NYC intersections would be safer if cars and pedestrians were more aware of each other. An unseen before reason of pedestrian error becomes a top 3 contributing factor during the most dangerous day (e.g, pedestrian confusion). Sharing the road and decreasing distractions on both sides will prevent injuries. I know I will think twice about running across the street at a green light as a New Yorker informed by Open Data.

Reproducibility and Resources

Check out my repository and let me know if what you think!

Resources I’ve found along the way.

NYC Action Plans for Vision Zero and Pedestrians Safety

Models Focused on Driver Attention

Citi Bike System Data

NYC New Driver Applications

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