Mental workload and determination of its relationship with situation awareness and work experience among taxi drivers

Investigations show that human error is one of the main reasons for driving accidents. Drivers' performance is shaped by various factors such as age, gender, driving environment; which one of the most important factors is the workload. The current study aimed to investigate the relationship between mental workload, situational awareness, and drivers' work experience.

Twenty-six taxi drivers with different work experience, dividing into two groups, participated in this study. Driving activity load index (DALI) was used for assessment of drivers’ workload and participants’ situation awareness was measured by situation awareness global technique (SAGAT).

The results show that driving in a long time will increase the mental workload in all dimensions of the driving activity load index (p <0.05), among which, the highest correlation is related to visual demand (r = -0.397, p = 0.045). There was a significant relationship between increasing workload and drivers’ work experience (p = 0.01). The results also showed that, as drivers’ mental workload increases, their global situation awareness decreases (p <0.001).

The results of this study indicate that increasing driver’s work experience, results in decreased mental workload, and global attention and situational stress are factors with the most different amounts among people with different work experience. Also, increasing workload, lead to decreasing perception level in situation awareness; drivers with more work experience have less decreased amount in perception level. Decreasing perception level in drivers leads to decreasing global situational awareness.
Key words: Driver's mental workload, Situation awareness, Work experience