How does population density affect how people travel in japan? ( need answer asap! )

How Population Density Affects Transportation 

Crowding has a big effect on transportation. What happens when millions of people in a huge city all head out for work in the morning?
It takes a long time to get there! The average commute time in Tokyo is an hour and a half each day. This adds up to nearly 400 hours every year. That’s enough time to watch 160 movies or take 40 flights from Tokyo to San Francisco. And some people’s commute time is much higher than the average.
Public Transportation The Japanese have adapted to busy rush hours by creating an efficient public transportation system. Underground subways link one part of a city to another, while trains carry people from town to town. Japanese subways and trains run often. And they almost always run on time—to the minute. You can set your watch by them.
Rush hour in the Tokyo subway is an amazing sight. People wearing white gloves stand on busy platforms. The job of these pushers is to shove as many passengers as possible into the cars before the doors close.
The Japanese have developed some of the fastest trains in the world. Bullet trains—named for their shape and speed—called Shinkansen travel between many cities. These trains travel at speeds of up to 180 miles per hour. That’s more than three times as fast as cars moving on highways when there is no traffic.
Private Cars and Parking Problems Despite their excellent public transportation system, many Japanese have their own cars and love to drive them. As car ownership has increased, so have major traffic jams and parking problems.
Parking is such a problem in Tokyo that the city has strict rules about car ownership. If you live in Tokyo, you cannot own a car unless you can prove you have a place off the streetto park it. Tokyo has also built high-rise garages that look like giant shoe cabinets. These garages use computer-controlled elevators to stack cars on top of one another.