Good question, hypothetical reader! IRL the answer is style and money, the latter of which applies in-game too. More importantly though, your cims select their routes based on time-to-destination, assuming no traffic (I don’t know this for a fact, but I’m pretty confident it’s mostly true). This means they’ll tend to funnel towards the larger roads, if given the choice.
That in turn means that, as planned, the only traffic on local roads is going to be those cims who have to use them.
Even with relatively long stretches of high-density development, that’s only a few sims an RL minute at the fastest speed, versus many, many more on the bigger routes. (The following is based on 15 minutes of me watching intersections with a stopwatch).Ĭonveniently, intersection signals in Cities: Skylines seem to be based on detectors: they’ll stay green for the last direction to have traffic, until either ~5 seconds elapse or vehicles arrive in a conflicting lane, whichever comes first. If both roads have similar loads, that’s 50% green time for each, cutting the capacity of both in half.
