Tuesday, June 25, 2019

WMATA - Introduction

There are 6 colored lines and 91 metro stations. Many stations are on multiple lines and that is something we must account for in our exploratory analysis.

  1. Red - 27 stations
  2. Orange - 26 stations
  3. Blue - 27 stations
  4. Green - 21 stations
  5. Yellow - 17 stations
  6. Silver - 28 stations

Elevators and Escalators

There are a combined total of 892 elevators and escalators within the WMATA system There are 277 elevators, and 615 escalators. Below is a breakdown by line color (and includes overlap stations):




Red Orange Blue Green Yellow Silver
Elevator 76 74 76 54 61 94
Escalator 203 214 234 162 177 234

Initial Hypotheses

  • Are more escalator and elevator outages reported on certain days of the week?

  • Are escalator and elevator outages reported more during certain times of the day?

  • When elevators and escalators are inspected less frequently, will more break downs occur?

EDA: Day of Week

EDA: Time of Day

Initial Hypothesis
The DC Metro’s system of escalators and elevators disproportionately affect travelers by being closed during Rush Hour. “Rush Hour” to be defined as between 7:00-9:00am and 4:00-6:00pm.

Data-Driven Hypothesis
The spikes at 9:00am and 11:00am to be caused by the reporting officials to start their days/report the maintenance findings during those times.

Breaks Reported During a Day

Breaks Reported on Saturdays

Breaks Reported on Sundays

Breaks Reported on Mondays

EDA: Inspection

  • Breaks appear to increase as inspections increase.
  • Counter to expected findings.
  • What could be causing this?

Data-Driven Hypotheses

Monthly Average Downtime

  • Downtime throughout the year is consistent.

Inspections Per Month

  • Inspections are mostly uniform throughout the year.

Time of Month vs. Downtime

  • Slight positive correlation between day of month and downtime.

Seasonal Trends in Downtime

Remaining Months

Remaining Months

Bonus: Predictive Model

Confusion Matrix

##          Actual
## Predicted    No   Yes
##       No  29260 10298
##       Yes   202   261

Fit Statistics

##   Accuracy Rate      Error Rate     Sensitivity     Specificity 
##          0.7376          0.2624          0.0247          0.9931 
## False Positives 
##          0.0069

Discussion

  • Outages are often unreported or reported the following day causing a spike in sudden closures.
  • There is no indication that inspections influence breaks.
    • Are inspections ever done retroactively?
  • Downtime is relatively uniform throughout the year, but some indications of seasonal variation may inspire further research
    • Holidays and weather could be factors

References

Appendix 1 Data Frame: Unit_Status

This data frame is powered by the DC Metro Metrics application which includes a list of all stored “unit statuses” between June 1, 2013 and February 22, 2015.