I was reading about circuits on this link, where they use a tollbooth analogy to explain electricity. Now either this is a bad analogy or I am missing something, but let's consider a circuit that consist of one resistor in series, followed by 2 resistors in parallel. By adding resistor to the parallel part of the circuit, the overall current increases. Let's say the first resistor is a tollbooth, that passes through 1 car per second. Isn't that what determines the current in the whole circuit? The current is 1. Why does adding more tollbooths in parallel speed up the cars? I understand they could go faster, once they pass the first resistor. But why are they able to pass it faster?
To ask it another way, if you are able to eat 2 cookies per second, but I am only giving you one cookie, you can't eat 2 of them each second. Now it doesn't matter if suddenly you can eat 3 cookies per second, if I am able only to give you one.