Quantitative Comparisons between truck drivers and city bus drivers: How do they differ?
As we have said, professional drivers as a group are exposed to very high levels of occupational stressors and all have much in common. However, each driver profile also faces a specific set of stressors. We used the OSI to compare 69 truck drivers and 130 city bus drivers. The mean total OSI scores were very high for both groups (65.2 +/- 3.6 and 68.7 +/- 3.8, respectively)(Belkic 1995). One important difference is that city bus drivers face predominantly overload, while truck drivers are exposed to a mixture of underload and overload. This combination is not a healthy one for the nervous system or for the cardiovascular system, as pointed out by stress experts Drs. Marianne Frankenhaeuser, Gunn Johansson (1981) and Lennart Levi (1981). When driving on long routes, truck drivers have a relatively low flow of new information (monotony) and frequently drive alone which is another source of underload as well as social isolation. At the same time, they still must keep their sensory system
