More dense, tightly packed cities build in this direction to maximize land-use. Prevalent in North American cities, and tends to be limited in most European cities due to building height restrictions.
What is up?
Single family homes detached with small yards are characteristic of this density area.

What is medium density?
Integration of commercial and residential areas to maximize space use especially in high income residential zones to reduce urban sprawl.
What is mix-use land development?
Undeveloped land around urban and suburban areas is called this? 
What is greenbelt?
A language which is commonly understood and used even by non-native speakers.
What is Lingua Franca?
Range, threshold, and hexagonal market areas all explain the location of human settlements and goods provided in a residential area is part of this theory.
What is Chistaller's Central Place theory?
What are primate cities?
Open space, sparsely populated towns, are known as this density area.
What is low density?
An New urbanism design initiative attempting to preserve farmland by specifically reducing this phenomenon.
What is urban sprawl?
Reduced urban sprawl, increase affordable housing and mixed-use neighborhoods are part of what solution focused of new city designs.
What is New Urbanism?
A mixed language deveoped from a pidgin to a unique distinct language combining colonial language with an indigenous language.
What is creolization?
The McGee model, based on Bangkok, Thailand replaces a CBD with this as the source of central economic activity.
What is a port?
Communication, roads, highways, bridges, airports, hospitals, water and sewage systems, electric grid (power lines) etc. all classify as this very important part of cities.
What is infrastructure?
Highly populated cities (areas) with large number of people living per unit of measurement (sq. m or sq. k).

What is high density area?
Society, the environment and this entity is involved in the impact and creation of infrastructure.
Using tax dollars they build and maintain it; the best infrastructure tends to see the most economic development.
What is local government / politics?
Increased walkability; access to mass-transportation, and creating mixed-use land to optimize the growth of cities is known as this sustainable solution.
What is smart-growth?
The reduced interaction between locations due to more space between them.
What is distance decay?
The most contemporary model of cities internal structure in the U.S. and Canada. Creates edge cities through beltways and highways around the main CBD.
What is Galactic city (peripheral) model?
The spatial patterns of economic and social development rely on these 2 aspects of infrastructure. Clue --> Where is it? How good is it?
What is location and quality?
Pollution, strain on resources, and the transportation nightmare that is Rush hour in major cities called this, are a few of the major issues facing growing cities.
What is traffic congestion?
As smart-growth policies and new urbanism initiatives are implemented, this problem arises as a result of increased demand and cost of those areas. Examples Detroit, Chicago, Memphis.
What is de facto segregation cities?
A phenomenon in which technology improvements have seemingly made the world shrink.
What is time-space compression?
The Griffin-Ford model in Latin America includes in Situ accretion, gentrification zones, and this long extending corridor from the CBD in which high-income elite residential areas are adjacent to.
What is a spine?
In Mexico city, this safe and fast method is being used to connect communities on the outskirts to jobs and opportunities in the city. 
What are aerial trams? Gondolas in the air?
Cities such as Los Angeles, New York City, Munich all must contend with very high housing cost by potentially implementing this new urbanism initiative to reduce cost of living.
What is increase affordable housing?