Question

Use the map to answer the question.

A map of the United States shows total annual transit trips by city, including rail, bus, or other forms of public transportation.

Each city is represented by a circle whose size corresponds to the total number of transit trips, with an example scale below showing circles for 35 million, 100 million, 350 million, and 4.2 billion trips. New York City had the greatest number of trips at 4.2 billion. Other large circles are located in the major eastern cities: Boston, Philadelphia, Washington, D.C., and Baltimore. In addition, there are large circles near Chicago, Los Angeles, and San Francisco. Medium circles surround the cities of Honolulu, Seattle, Portland, San Diego, San Antonio, Denver, Minneapolis, Dallas, Houston, Atlanta, and Miami. Smaller circles are found near San Jose, Salt Lake City, Las Vegas, Austin, Phoenix, Cleveland, Detroit, St. Louis, Pittsburgh, and Milwaukee. Rail service is available in all places except Honolulu, Las Vegas, Austin, San Antonio, Detroit, and Milwaukee.
Examine the map.

In 1–2 sentences, identify the relationship between rail availability and levels of public transportation usage suggested by this data.
In 1–2 sentences, describe the way in which public transportation usage is more sustainable than individual use of gasoline-powered cars.
In 2–3 sentences, analyze the relationship between sprawl and the use of public transportation, and then explain steps cities can take to increase sustainability.

Answer 1

The map suggests a strong positive association: cities with rail service tend to have much higher total transit trips (larger circles), whereas places without rail are generally among the smaller transit systems — although this is correlational, not proof of causation.

Public transit is more sustainable than individual gasoline-powered cars because it moves many people with lower energy use and emissions per passenger, reduces congestion, and requires less urban land for parking and roads.

Sprawl—low-density, separated land uses—makes transit slower and less convenient, encouraging car dependence and higher per-capita energy use. To increase sustainability, cities can pursue compact, mixed‑use and transit-oriented development, expand frequent reliable rail/BRT and multimodal connections, and use policies such as reduced parking minimums and congestion/parking pricing to discourage driving and boost transit use.