(kiddie music)

(cans rattling)

(buzzing of train on track)

- If you live in a big city, and even if you don't,

you've probably seen trains like this.

They're called rapid transit trains.

When the tracks go underground, it's the subway.

When the tracks are up over the streets,

it's the elevate or el train.

In the late 1800's, America saw a couple of big changes.

One, bigger business meant the growth

of big cities likes New York, Boston, and Chicago.

Two, many of these urban areas became electrified.

That meant more business, more people and more traffic.

The problem was how to move all these

people quickly and efficiently.

Horse drawn street cars were slow,

smelly and held a limited number of riders.

- [Background Voice] You stink.

- Also, more and more gas powered cars

clogged the streets, making the problem

of moving many people harder.

One answer was to get off the streets and go under them.

In 1894, Boston started the first subway system in America.

New York soon followed.

Tunnels were dug under the city streets

with rails laid for electric powered train cars.

Around the same time, Chicago figured

why not go up as well, they built an elevated system

called the el in the downtown area known as the loop.

The tracks were over the streets,

allowing road traffic as well as rapid transit.

Everybody knows a train runs on two tracks

but guess what, rapid transit trains have a third rail.

Why? That's where they get their power to run.

These trains run on electricity,

100's of volts that move through a contact shoe

that drive electric motors attached to the wheels

and that third rail is dangerous.

Stay away from it.

Two or more cars make up a train.

They move from station to station

where passenger hope on or get off,

going to and from school, work, shopping and more.

The riders have to be quick, the train stops,

the doors open, and in less than a minute, they close.

The train heads off to its next stop.

Today, many cites all over the world rely on

mass transit systems to move people

from one place to another quickly and safely.

In America, cities like Washington D.C.,

San Francisco, Detroit and Salt Lake City

along with long timers like New York,

Boston, and Chicago all proudly boast

about their subway and elevated trains.

Rapid transit, come on and get on board!

(train horn)

(buzzing of train on track)