In short, there are a number of salient factors that act as mediating variables in the way that stressors appear to cause strain for the commuter: Impedance, lack of control, the variance and predictability of travel time, physiological responses, personality and cognitive style, and finally noise and crowding. Obviously, there is much overlap and interaction among these variables especially in the interplay between subjective, perceptual factors and objective stressors. The presence of these variables in the commuting experience highlight the probability that the strain of commuting is likely to spill over in some way to the commuter’s home life. But these variables also suggest that the degree and nature of the strain may vary from commuter to commuter, since no two commutes are identical.

Behavioral, Emotional and Attitudinal Effects

            Much of the research on the effects of commuting has been done within the context of organizational behavior. Koslowsky (1995) summarized this literature around the effects of absenteeism, lateness, turnover, and performance. Absenteeism, lateness and performance deficiencies do not appear to be associated with commuting variables. However, one study found that commuting satisfaction was related to job change (Novaco, Stokols, & Milanesi, 1990). It appeared that people tended to change jobs based on whether their commute was satisfying rather than whether their job was satisfying. The precise significance of this for the home environment is not entirely clear. This is due, in part, to the fact that most studies of this nature are done with the concerns of organizational behavior in view. It is also difficult to assess the significance of this for the home environment because the decision to change jobs due to a stressful commute may indicate characteristics of the commute or of the commuter. The commuter may be changing jobs for one of several reasons. For example, the decision to change jobs may indicate either that the commute was an enormous strain or a higher degree of coping skills displayed in the decisive action to change jobs. Either or both of these could have implications for the home environment (Koslowsky et al., 1995).

            More recently, the effects of commute travel impedance on the home environment have been studied. Ninety-nine employees of two companies in Southern California were studied in order to investigate the effects of physical impedance and subjective impedance on residential satisfaction and personal affect in the home (Novaco, Kliewer, & Broquet, 1991). Novaco and colleagues conceptualized the relationship between impedance and stressful consequences in terms of an ecological model which places emphasis upon the reciprocal links between life domains. Within this model, the psychological consequences of environmental conditions in one domain of life (e.g., home or work) spillover to another domain. According to the rubric of the model, the spillover effects are referred to as interdomain transfer effects. Specifically, interdomain transfer effects have been found between home and job (Novaco et al., 1990).

            In their 1991 study, Novaco and colleagues hypothesized that both physical impedance and subjective impedance would have adverse effects on various home environment measures: mood at home in the evening, conflict at home, various residential satisfaction measures, and personal dysphoria. They also hypothesized that home effects of physical impedance would be moderated by gender, but more so by subjective impedance. For example, if men or women perceived a high number of traffic jams (subjective impedance), the effects of the real number of traffic jams (physical impedance) would have a greater negative impact on their experience in the home domain.

            While findings indicated that physical impedance had a highly significant negative effect on mood at home and a significant effect on personal dysphoria, their first hypothesis was not confirmed with respect to conflict at home and residential satisfaction. However, subjective impedance was found to be a significant moderator of the effects of physical impedance on negative mood at home and dysphoria. Scores on measures of negative mood at home and personal dysphoria were higher for women in the medium and high levels of physical impedance than for men and approached significance. Women in the high physical impedance group appraised their commutes as being more of a strain than did men in the same condition. This gender difference was especially true for the morning commute. This was so despite the fact that men and women in the sample did not differ significantly in the number of stops to and from work. Because findings also suggested that women reported feeling more rushed to get to work than men, Novaco and colleagues suggest that the high appraisal of subjective impedance on the part of women is due to women having more home responsibilities before they begin their commute in the morning (Novaco et al., 1991).