Are transit system maps too complicated? Human beings can only process a finite amount of information at once (eight bits, or yes/no decisions—on maps that would mean 2⁸ or 256 connection points); researchers examining the transit systems of 15 large metropolitan areas found that many trips exceeded that eight-bit limit, especially when multi-modal trips (e.g. subway plus bus or tram) are involved (subway-only trips tended to fall under the limit). System maps with too many data points are overwhelming. “We have found that, in the largest cities, the addition of bus routes with maps that are already too complicated to be used easily by travelers implies that the cognitive limit to urban navigation is exceeded for multimodal transportation systems.” A single map, in other words, is no longer sufficient or useful in such cases. [via]