When i'm playing on the server and my internet is lagging, my car is teleporting somewhere or time is slowing down and then speeding up. I'm just wondering why the game needs stable internet connection. I think it shouldn't happen because there's no interaction with other players.
Hey twixuss., thanks for reaching out and apologies about the delayed response from our team.
Offline is possible and you can play without internet connection however you will be limited to Local Play only.
As far as the gameplay goes, we would not be able to dive too much into detail regarding connection and why is it needed however to keep it simple - each time you're starting anything outside the Local Play, you are in process of connecting to server which will require connection at all times. Having poor signal will result in what you've described in your initial post and will make in-game experience a lot more complicated.
Should you have any further questions, let us know!