As noted in Brief 12, the auto boom appears to have completed its rapid growth cycle and has stabilized at very high levels, remaining the dominant mode. However, in the past decade or so, there are signs of auto commuting retrenchment and evidence that transit has increased as a commute mode. This brief presents data describing transit commuting trends and relationships. It should be noted that transit use, which hovers at around a 5 percent share for commuting, is more challenging to comprehensively analyze with statistically-significant data due to its modest share and the constraints of sample size in both American Community Survey (ACS) and National Household Travel Survey (NHTS) data sources. Thus, some of the geographic and socio-demographic richness available for private vehicle commuting, particularly for smaller geographies, is more limited in the case of public transportation.