

Micromanage which vehicles are allowed in 'special' lanes to allow your critical infrastructure to continue working while cars are in a traffic jam.(By default all directions are allowed, that might be pointless, and removing some can speed up traffic light rotation) Micromanaging which turns are allowed on intersections.traffic light programming, fine-tuning the amount of lanes for each direction). Micromanaging how intersections work to get more mileage out of them.Fine-tuning road shape for realism and efficiency.Take a look at for example the steam workshop. There's mods out there that allow you more control over your roads.

Here's some ways of dealing with heavy traffic when you've got important services. Eventually the city hits the vehicle limit and agents start teleporting (if you modded the game to remove this sillyness, the problem gets worse). Thus, if there's a bottleneck, the traffic will start expanding until every agent that goes through is stuck in that bottleneck. Traffic is basically constant for any reasonably sized city.

Unlike in reality, due to the time compression, traffic doesn't come in huge waves (when commuters go to/from work) with the downtime in between allowing the built up congestion to peter out. If it fails, so will the city (eventually). Nearly everything in the game ultimately depends on the road system functioning. It's likely your other services work just by the virtue of having a large overcapacity, or, in a young city, not enough built up demand to stress the system yet (thinking of healthcare and funeral services). Another way is to increase capacity, but that means likely running out of money. You could try to increase the density of the city, but that will most likely just compound your problems. Schools aren't effective if it takes a week to get there, and agents aren't smart enough to realize they can walk there faster than going there by vehicle. That means if your roads are clogged, the vehicles that actually do their jobs of, say, driving schoolchildren to education, can't do so effectively enough to fully utilize the capacity of the buildings. Now that I think about it this is true of most games. This means people spend most of their time going to places, not actually doing stuff. The main question is 'how bad'? Sub-10% flow rate is where things start to really break down. That means a day is only perhaps a few minutes long. I've got some bad news here: Cities Skylines is an agent based simulation.
