Commuting Stress , Ridesharing , and Gender : Analyses from the 1993 State of the Commute Study in Southern California

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. Commuting Stress, Ridesharing, and Gender:. Analyses from the 1993 State of the Commute Survey in Southern California Among the external costs believed to be associated with traffic congestion are the human stress effects. Remaining attached to the private automobile travel mode and constrained by the availability of affordable housing, workers endure congested commutes and absorb the stressful consequences. Indeed, the stressful effects of chronic exposure to traffic congestion and other dem~mds of long-distance driving in commuting between home and work have been demonstrated in a series of studies (most recently, Novaco, 1992; Novaco, Stokols, & Milanesi, 1990; Novaco, Kliewer, & Broquet, 1991). In these studies, traffic congestion has been understood to be stressful by virtue of its impedance properties. That is, it operates as a behavioral constraint on movement and goal attainment, thus constituting an aversive, frustrating condition. As such, it elevates physiological arousal, elicits negative emotional states, and impairs cognitive performance. This research has found that high impedance commuting, indo:ed by objective and subjective dimensions, has adverse effects on blood pressure, mood, frustration tolerance, illness occasions, work absences, job stability, and overall life satisfaction. The methodology used in this research program on commuting stress has been a measurement-intensive, quasi-experimental field site testing procedure that has incorporated many control variables as covariates in the analyses. However, this methodological rigor has come at the expense of assurances regarding generalizability, due to the relatively small samples sizes (each of these previous projects has involved approximately 100 participants) and the location (all studies were conducted with companies in one city). The present study, therefore, examined commuting stress associated with automobile travel in a much larger geographic area with a large representative sample of commuters. For this purpose, several items pertaining to commuting stress were added to the southern California "1993 State of the Commute" survey. Collier & Christiansen (1992a & 1992b) have reported the results of this survey on previous years. The newly added items sought to index commuting stress in terms of the aversiveness of the commute and the negative impact of traffic exposure on work and home life. Ridesharing has been promoted as an alternative commuting mode to reduce traffic, air pollution, and stress. The present study also examined the merit of ridesharing in comparison with solo driving regarding the stress effects of long distance commuting. National trends in commuting patterns have indicated that increases in the workforce, in the availability of automobiles, and the shift of jobs to suburban locations have significantly increased commuting by private automobile (Pisarski, 1987). From 1960 to 1980, travel to work by private automobile increased from 70% to 85% nationally, while use of public transit declined from 12.6% to 5.2% (Pisarski, 1987). While increased congestion and air quality management regulations have prompted ridesharing programs, Teal (1987) has shown with national data that the large majority of drive-alone commuters lack any transportation or economic motivation to carpool. In California, road use charges are virtually nonexistent, gasoline remains inexpensive, and nearly everyone who needs a car has one. The impact of the latter is illustrated by the fact that from 1980 to 1989, many California counties have had a greater proportionate increase in registered automobiles than in population. For example, the population of San Francisco County increased by 50,400 (7.4%) during those years, while the number of registered automobiles increased by 49,835 (18.8%). The corresponding figures for Santa Clara County were 154,200 (12%) people and 183,643 (25.4%) autos; for Los Angeles County 1,205,900 (16.2%) people 870,191 (23.6%) autos; and for Orange County 357,990 (18o6%) people and 330,621 (30.8%) Regarding reducing the demand for road space, transportation alternatives to solo driving in southern California have only made small gains. Analyses of the first year results of the trip