First of all, I wish you a good day. I hope you had a great day.
The lags are due to Truckersmp and this is because it is not optimized. To get into a more technical area, the maximum TC value of the game (maximum 1 million points) increases at least 4 times in crowded areas, and due to this factor, your game lags and/or hangs. As a solution to this, you can lower your graphics from both Tab settings and game settings. Of course, a better system can reduce latency, but it won't eliminate them completely.
I hope what I wrote helped and your problem was solved. If you need help you can contact me
Have a nice day,
Kind regards,
Samderali.