Context: Vanilla (no mods just yet), Steam edition, Linux
After reading the Prima guide, Z's various notes about the traffic simulator, and Corina's experiments with forcing mass transit use, I've been running some silly layouts of my own. One such layout is a kind of "arcology" concept borrowed from SimCity 2000, since that's the one from my youth. The arco is a large outer block of avenue with 19x19 interior space, a 4-deep ring of residential (or commercial) high-density zoning whose street-level access carat points to the avenue, and an inner ring of streets. At the four interior corners of the street ring, I place subway stations. A residential arco's interior courtyard has schools, a hospital, and some parks, while a commercial arco's inner courtyard gets plazas and/or low-density commercial zoning.
Traffic-wise, this works pretty well. The avenues have hundreds to maybe 1k drivers on them, and the subway stations end up with several thousand users each. Even with doubling and tripling up on subway lines, the subway lines in-between the arcology blocks will light up red with congestion. All of that is actually working as intended.
The weird part is the pedestrian traffic. The handful of street tiles in-between a heavily used subway station and a major building can easily have 2-3k pedestrians on it. And that level of pedestrian traffic creates congestion! The map gets colored red and the news calls it out, too. There is not one car on those streets, yet they do get congested with the ped traffic. Upgrading them to roads clears the congestion.
Is this something that others have encountered before? Prima's guide and Z's notes both suggest that pedestrians really shouldn't cause congestion. Yet... there it is.
