Urban geography questions? Pretty please answer

Hey, I have two questions here and I don't really care how much of the questions you answer, go for as little or much as you want, any information you could provide me with is much appreciated. Thanks :)

The evolution of the American City has been largely influenced by improvements in transportation technology. Discuss how each of hte following affected the growth and geography of a large American city:
a) street cars and subways (1900-1930)
b) highways (1950s-present)
c) new light rail and subway systems (1970s-present)

North American metropolitan areas face many challenges. Discuss in detail one social, economic, and physical challenge for each of the following areas:
a) Central Business Districts
b) inner city neighborhoods
c) inner ring suburbs (1950s)
d) edge cities (commuter zone)

Street cars and subways, being LINES rather than networks like streets and roads, served to extend city growth in lines outward from center, kind of like a star with narrow points.
Highways allowed a huge expansion of urban areas into what became "bedroom communities" (suburbs) because of the distance that a car could be covered in a one-hour or less commute, keepiing in mind there were much fewer cars on the roads back in the 1950's.