kick in
And then there is the transportation thing .I mean, to get a carton of milk you have to drive 3 miles. So the whole car culture thing kicks in.
question:what does "kicks in" mean?

Question

kick in
And then there is the  transportation thing .I mean, to get a carton of milk you have to drive 3 miles. So the whole car culture thing kicks in.
question:what does "kicks in" mean?

Answer

In this context, it means "begins", "begins working/to happen" or "becomes evident". Here are some more examples:

The moment the burglars opened the safe, the bank's alarm system kicked in.

I took two painkillers and waited for the paracetamol to kick in.

In the third mile of my run, I felt the endorphins kick in.