# Segmentation

It is important to note that the problem formed in the previous blog

The Problem Statement

is not final.  It was just an initial statement based on what we knew at the time.  And sometimes what we thought we knew was not factual.  So naturally, the problem statement may require revising multiple times as we move through and analyze the empirical data.  We analyze the empirical data in order to better understand the problem with the purpose of, in the end, identifying a root cause to go fix.  As it stands now, here’s what we say we know based on the problem statement.

1.  Around the beginning of July, we began noticing cars speeding through Palm Desert on 23rd St.
2. Cars are speeding in both the north and south direction.
3. Children are at play, putting them at risk

Now it’s time to look at the actual data.  The community president and I go out and spend several hours a day for a week observing the problem area.  In the end, we build a list of all the “What we know” and “What we do not know” about the problem.  Here’s our list.

What we Know

1. Approx. 40% percent of the vehicles moving in the north direction on 23rd St. were speeding.
2. Approx. 1% percent of the vehicles moving in the south direction on 23rd St. were speeding.
3. The main artery, 24th St., is currently under construction.
4. The 24th St. construction began on July 5th.
5. On the south side of the construction project, workers are consistently crossing over open lanes in order to retrieve material from their staging area, often slowing down approaching vehicles.  This is not the case on the north side of the construction project.
6. Going south on the main artery, the traffic seems to be flowing without issue.
7. Going north on the main artery, the traffic is frequently being backed up.

What we do not know

1. How does the traffic normally flow when there’s no construction happening on the main artery.

Whew….problem solving can be an exhaustive undertaking.

Anyhow, I think our segmentation work is paying off.  We know that construction is taking place near our neighborhood and seems to correlate to when we started noticing cars speeding through Palm Desert.  However, our data suggests that the issue is not bi-directional.  There are a high percentage of cars speeding in the north direction and not in the south direction.  This fact will require us to revise our problem statement.  Lets do that now.

Starting around the beginning of July, we have observed an increase in speeding cars through Palm Desert going north on 23rd St., increasing the risk of injury to children playing in the neighborhood.

That should suffice.

In the next blog we will build a working model that can explain why cars are speeding through our neighborhood.