SimCity traffic problems being fixed, says Maxis.

SimCity lead designer Stone Librande has posted a blog detailing how the game's simulation mechanics work, and has pledged to fix the game's traffic pathing.

This week numerous YouTube videos have surfaced from users who have found ways to highlight bugs and errors in SimCity's simulation. Librande has clarified how the game's GlassBox engine processes information. "At the surface level, GlassBox is designed around the premise that 'Agents' are created to carry data to various 'Sinks' around the city. In SimCity, you can think of the 'Agents' as Sims and vehicles. The 'Sinks' are the buildings that receive money, happiness and other resources from these Agents."

"Our main focus right now is updating the pathing system that the Agents use to get to their Sinks. Running a successful city means keeping the traffic flowing and we are actively working to make this system better," Librande added. "One of the main bugs being highlighted at the moment is in the game's traffic system insisting on taking the shortest possible route to each location, causing massive traffic jams even when other roads are available."

"We understand that when cars always take the shortest route between point A and point B there will be unavoidable (and illogical) traffic jams, so we are returning these values to make the traffic flow more realistically," said Librande.

"To dig a little deeper," Librande added, "our roads will have a weighting system based on 25%, 50% and 75% capacity. As a road hits those marks it will become less and less appealing for other cars, increasing the likelihood of them taking an alternate path if one exists."

The traffic situation will be patched shortly, says Librande, and the fixes are being tested internally at Maxis right now alongside other pathing issues, such as with multiple emergency services responding to issues one by one as opposed to simultaneously.

"We are working on additional fixes with the pathing of our Agents and these changes will streamline the way that the simulation unfolds in your city. For instance, emergency vehicles will not get blocked in their garages and will move into empty lanes to get around traffic jams. We're also working on preventing service vehicles from clumping up (for instance, only one fire truck will respond to a fire instead of two) and improving the way that Public Transportation operates in the city. We are currently testing a patch internally and hope to have it out to you soon."

Librande also detailed how some of the game's simulation mechanics actually work. He confirmed that SimCity's sims do not lead realistic lives, but instead move to the nearest available job in the morning and leave for the closest vacant house in the evening. It means a sim might go to a different job every day, and return home to a different family every evening.

"Ultimately we didn't feel that the cost of adding in that extra layer of micro detail made the macro game play richer. Game design is filled with tradeoffs and compromises like this and we are constantly evaluating these (and many other) decisions," said Librande.

Librande confirmed that Maxis is slowly reenabling the features it switched off last week to help ease the game's overloaded servers. Regional achievements are now live on select servers, and leaderboards are up and running on the game's test server. SimCity's cheetah speed is still unavailable, and was not mentioned by Librande.

Yesterday a SimCity modder showed it was possible to circumvent the game's 20-minute disconnection timer, essentially making it possible to play the game, which by default insists on an always-online connection, indefinitely online.