the only proper way to do it is to ravage through regions of my city to make massive interchanges and efficient routes

Accurate simulation then.

You can avoid the need for highways if you minimize car use via pedestrian-only roads and tons of public transit.

I always go with the following strategy:

• Tons of public transport to ensure that local commute doesn’t have to rely on cars. In general, if I start to get the feeling that I need to place a highway in the city to solve the congestion problem, then I look what route is under served by public transport.
  • Buses or trams (if I want to be fancy) for shorter routes, metro for longer distances.
  • Passenger trains for inter-city and longest local transport.
  • Cargo trains in industrial hubs, but careful with those, as they tend to generate a lot of traffic when trucks come and go. I usually do some sort of a traffic sponge (one-way road that leads only to the cargo train station) for trucks to wait without blocking other traffic.
• I use highways sparingly and only for longer distances, like connections between cities. I try to build them outside of the city, so it would also act as a bypass - the cars which are not going into my city but through it won’t generate traffic in the city itself this way.

I just make cities with no highway connections at all. It’s very easy to build your cities around train stations and public transport instead.

It’s complex. An intersection that works for an industrial block may not work for residential.

I generally go for a roundabout at ground level and a highway overpass for intersections.

Using transit to offload vehicles to rail which minimises the amount of highway needed.

Just do it, once your city has enough money if the bank, or your income is large enough, double down on making a highway. Demolish some buildings and tear your city in half, just like in real life. Most of the time if you have enough traffic that you need a highway in the town, you could probably avoid it in game, by enhancing the public transit options, however, that wouldn’t be realistic as to how cities are really run, so doing a highway every now and again is a fun change of pace.

The best way to get good at making a highway, is to make a highway, you can do it, set it up however you want, and see how it works. If something doesn’t work right, change it and find out how to make it work for you. Or if it is broken, it may be more fun to leave it broken. Stuff like that happens in real cities all the time.

Make sure you adjust your public transit options when you’re done splitting your city in half with your highway, since your bus routes will be interrupted.

I’m a longtime CS1 player. I use highways at times. Mostly for the grade separation aspect. I rarely feel the need to go above 2 through lanes each direction and 1-2 auxiliary lanes. Often I place 2 lane rural roads from the highway tab when I start building and leave land to preserve highway and rail corridors and upgrade them into freeways later. Don’t be afraid to leave too much land along a road you intend to upgrade as you can always add infill development later. I usually leave at least 20u in width when I first plop one down. Use the query tool on the segments where the highway meets other roads to determine where traffic is trying to go. Using fully grade separated, free moving designs then running a little highway spur for a few blocks, or even a 2+1 road helps with collecting and distributing traffic instead of having a giant stack interchange dumping right onto a 4 lane avenue with frequent lights. If you play with despawning off, signalized freeway exits can be nightmarish and often necessitate the use of timed traffic lights and significant lane math and movement restrictions.

Lastly, your industry should have a clear shot to the highway, maybe even designated truck lane(s). If all your trucks have to pass through an urban area with lights and peds to get to the freeway, you’re gonna have a bad time.

Hope some of this helps and I look forward to hearing other folks commentary. Good question.

Something else I can say is scale. If you’re building a realistic scale city, you don’t have a vast highway system. Highways in real life connect between cities. And good urban design should see highways outside of city centers and away from neighbourhoods for the noise. So in CS, a highway basically can just run past your city and connect your city to a fictional place outside the map. I think it can be interesting to think about what you want the history of your city to be. If it is a point that has always been between other big places, it might be near a big highway crossing where two highways meet, if it’s more of a coastal city or an “end point”, there only needs to be a highway leading to the city.

Some cities don’t have a highway at all and you need to drive quite far to get to the highway outside of town.