Abstract: To examine the variation law of the driving psychological load in subsea tunnels under different illumi- nation and longitudinal slope conditions, 22 drivers were recruited to participate in a real vehicle test in off peak hours under similar traffic conditions, and the skin electric signals of the drivers in the free flow state were col- lected. Considering the skin conductance level (SCL) as the load characteristic index, the influence of the different illuminance and slope conditions on the drivers’ skin electrical signals was analyzed, and a measurement model of the relationship between the uphill and downhill slopes, illuminance and driver’s SCL value was constructed. The results indicate that the illuminance change rate and driver’s SCL are positively correlated. A larger illuminance change rate leads to an increase in the SCL and psychological workload of the driver. The influence of the uphill and downhill slopes on the driver’s SCL value in different areas of the subsea tunnel is considerably different. With the increase in the degree of the uphill and downhill slopes, the driver’s SCL value increases, and the maximum SCL appears in a slope range of 3.5%—4%. Moreover, the SCL of the drivers in the downhill section is higher than that in the uphill section, corresponding to a larger driving psychological load.

Key words: subsea tunnel, skin electrical signal, driving psychological load, illuminance, longitudinal slope