Chart assignment

Charts to read and discuss

Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.

  1. Which US airports have the most delayed departures?
  2. How fast has the world come online?
  3. Are U.S. roads getting safer per mile driven?

Chart 1 of 3 · Air travel

Which US airports have the most delayed departures?

The interactive chart needs JavaScript. The numbers are on the chart's page.

In the 12 months through August 2026, 32.3% of flights leaving Dallas, TX (DAL) left 15 or more minutes late, the most of the 102 U.S. airports with at least 10,000 departures. Kona, HI (KOA) had the fewest, 13.7%; Atlanta (ATL), the busiest, was at 21.8%. Search for any airport by city or code.

Questions to discuss

  1. In one sentence of your own, what does this chart show?
  2. Find the biggest change or difference in the chart. What might explain it?
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

Chart 2 of 3 · World

How fast has the world come online?

The interactive chart needs JavaScript. The numbers are on the chart's page.

73.6% of the world's people used the internet in 2025, up from 15.6% in 2005, the first year the World Bank gives a world figure. It counts people who used the internet at least once in the previous three months. The world figures are estimates by the International Telecommunication Union.

How to read this chart

Each point is the share of the world's people who used the internet at least once in the previous three months, as estimated by the International Telecommunication Union. The axis starts at zero, so the height shows the true share. The steeper the line, the faster people were coming online.

Questions to discuss

  1. About what share of the world was online in the first year on the chart, and in the latest year?
  2. Did the share grow faster in some years than others? What could have sped it up?
  3. Using the internet once in three months counts here. What does this number leave out about how people get online?

Chart 3 of 3 · Road safety

Are U.S. roads getting safer per mile driven?

The interactive chart needs JavaScript. The numbers are on the chart's page.

In 2024 there were 1.19 deaths for every 100 million miles driven, down from 3.35 in 1980. The lowest rate was 1.08 in 2014; it jumped to 1.34 in 2020, when people drove less but deaths rose. Miles driven are the Federal Highway Administration's estimates.

How to read this chart

Each point is the number of people killed in traffic crashes for every 100 million miles Americans drove that year. Dividing by miles driven turns a count into a rate, so years when people drove more or less can be compared fairly.

Questions to discuss

  1. About what fraction of the 1980 rate is the rate in the latest year?
  2. In 2020 people drove less, but the rate went up. What could explain that?
  3. Why is deaths per mile a fairer way to compare years than the total number of deaths?

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