A stressful nature of exposure to traffic congestion in automobile commuting has been demonstrated in previous quasi-experimental research that has been measurement-intensive but conducted with relatively small samples. The present study examined commuting stress in automobile travel with a large representative sample (N = 2591) in southern California through telephone survey. Commuting stress was found to be significantly associated with distance and duration of the commute, controlling for age and income. As predicted, the stressful effects of long distance commutes (> 20 miles) were further moderated by gender, as women in such commutes perceive much greater commuting stress spillover to work and home. Some hypothesized stress-mitigating effects of ridesharing were found, as full-time ridesharers were significantly less bothered by traffic congestion and more satisfied with their commutes than solo drivers. In analyses of prospective adoption by solo drivers of alternative commuting modes, it was found that the perception of one's commute as having a negative impact on family life had a very significant effect on the inclination to try carpooling and train/rail, beyond the effect associated with distance itself. Commuting stress is discussed as an external cost of traffic congestion that is internalized by the solo driver. Marketing strategies for alternative modes of commuting might increase their effectiveness by highlighting stress consequences, especially negative impacts on family life.