What would correspond to the current, I?

Question

1. the rate at which cars pass a given point
2. the street    
3. cars
4. traffic signals

Answer 1

The rate at which cars pass a given point

As current I is rate of flow of charge or amount of charge crossing a cross section of wire per second

Answer 2

More currectly, the # of cars passing in a road may correspond to the current. Traffic signals are like different circuit elements. The street itself is the current carrying wire.