When it is snowy, the traffic is bed.= When it's snowy, the traffic is bad.

Public transportation is also crowded. 

There are only outside parking lot in my house, = There is only outdoor parking in my place.

I have to park outside my car. So if I drive my car when it is snowing, I have to clear the snow on the car. = I have to park my car outside, so when it's snowy, I have to clear the snow on the car.

The ground is frozen and dangerous, especially for older people. 

Sometimes it makes accident. = Sometimes it causes an accident.

In addition, shoes are getting dirty because of the snow. = In addition, shoes get dirty because of the snow.

If I go out with some shoes made of suede or leather, they are damaged by snow. = If I go out with suede or leather shoes, they get damaged by the snow.