[2020] Traffic Bug

This is normal to see. The traffic you're seeing is "dummy traffic" that keep the highways looking busy. Think of it like vehicles that are just passing by on their way - they don't need to stop in your city, but if the fastest way is through your city, they will take it.

There's a few ways to avoid it that don't require mods.

1. You can have your city be a "dead end" so there isn't a point for the traffic to go through your city.

2. You can give the traffic a way to pass your city without entering it.

3. Or you can add a little stretch of road, like in the screenshot, to let them turn around and not enter your city.