Stay vigilant or become a driving statistic

Maven Analytics Bootcamp Excel Project: NYC Traffic Data

The Situation: as a data analyst on the analytics taskforce of the New York City Police Department, I've been asked to analyze traffic accident data from Jan 1, 2022 up to Jan 30, 2023 as part of the city's Public Safety initiative. The data provided included 110,000+ records, each representing a vehicle collision that included details such as date, time, location, vehicle type, contributing factors, and more.

The Objectives: create a dashboard to answer the following questions:

• Do traffic accidents show any patterns throughout the year?
• During which time of day & day of week do traffic accidents occur most frequently?
• Are there any particular streets or intersections that carry a higher risk than others?
• What are the most common contributing factors for traffic accidents? What about the most fatal?

The Analysis:

Between Jan 1, 2022 and Jan 2023, there were 110,248 collisions and 41,651 injuries. This averaged to about 12 collisions each hour, with 4 injuries each hour — that's about 288 accidents and 96 people that get hurt each day! Thankfully, there have been less collisions when compared to the previous month and year, but in January 2023, despite there being 1218 less collisions, more of these resulted in injuries, 175 to be exact.

Something that was surprising to learn as a Canadian (brr, our winters) was that there are more traffic accidents in warmer months compared to the winter months. I was surprised as I was expecting that with icy roads, there would be higher risk. When I looked into this, it turns out that because of increased vigilance and slower driving speeds during the winter, there are actually less accidents. On the opposite end, during the warmer months, the mild/warm temperatures promote an inflated sense of safety, resulting in increased driver complacency and likewise, vehicle collisions.

Beyond seasonality, we also see a spike in accidents during the rush hours of 7-9AM and 4-5PM. This is likely because of the increased amount of drivers of road, as well as driver complacency and inattention due to routine drives and decreased energy levels during these parts of the day. In other words, be careful on the road when coming home from work. This especially holds true on Fridays, the day with the most collisions, potentially because drivers rushing to get home or to their weekend plans.

But with this all talk about driver inattention and complacency, is that really what's causing accidents? The answer is a resounding yes. For collisions overall as well as collisions that resulted in an injury, more than 30% of the main contributing factors were due to driver inattention. This is 2-3x higher than the next contributing factor—failing to yield.

Leading up to our conclusion, where can we focus campaigning efforts and where should we investigate? As it turns out, Belt Parkway, Broadway, Brooklyn Queens Expressway, Long Island Expressway, and Atlantic Avenue are the top five streets in number of collisions during this time period. We expand a bit more in the following section:

The Recommendations:

Driver inattention during peak seasons, weekdays, and hours can likely be contributed to complacency arising due the nature of said seasons, weekdays, and hours. My recommendations are as follows:

• Focus campaigning efforts on driver vigilance vs inattention
  • There should be efforts on both encouraging vigilance and discouraging inattention/complacency.
• Strategic placement of campaign signage around high-collision areas
  • Use statistics so that drivers can be able to better quantify their risk or even know that they're at risk at all (warding off complacency and introducing increased vigilance)!
  • Speaking of statistics, some drivers may be aware that there are increased accidents in the warmer months vs. colder months or that rush hour is prime time for accidents, but do they know the specific numbers or proportionality? Statistics can show them.
  • Signage placement needs to be critically considered: too much signage in the actual street itself may actually serve as another environmental distraction.
• Campaigning towards drivers that may feel like the risk of injury/death is low for them
  • Again, statistics and graphics, as well as advertising can help quantify risk while also reminding drivers that they risk not only themselves but the people around them.
  • We can survey drivers on their perceived level of risk and complacency.
• Preparing summer campaign: increasing awareness of dangers of driving during warm months
  • Dangers include: driver inattention, impacted vision and driving conditions, driver irritability, and passenger distraction
• Investigate high-collision streets for environmental distractions
  • What other reasons could there be for why the Top 5 high-collision streets have so many accidents? Are there other distractions? Are the road conditions unsafe? Are the speed limits appropriate?

In conclusion: we need to increase driver vigilance during times of perceived lack of danger.

---

Created by: Mars Huynh | Data Analyst