Train driving efficiency and safety: examining the cost of fatigue.

This study investigated the effects of fatigue on train driving using data loggers on 50 locomotives operated by pairs of male train drivers (24-56 years) on an Adelaide-Melbourne corridor. Drivers' work history was used to calculate a fatigue score using Fatigue Audit Interdyne Software. Trains were assigned to one of three groups, based on drivers' maximum fatigue score: low (n = 15), moderate (n = 22) or high (n = 13) fatigue. Changes in driving parameters at different fatigue levels were investigated. A significant (P < 0.05) increase in fuel use was observed. Drivers in the moderate fatigue group used 4% more, and drivers in the high group used 9% more fuel than drivers in the low group. As these trains run daily, taking horsepower into account, this represents an approximate extra weekly cost of AUD$3512 using high compared with low fatigue drivers. High fatigue-group drivers used less throttle and dynamic brake and engaged in more heavy brake and maximum speed violations. Comparison of three, 100 km track sub-sections with undulating, flat, and hilly grade indicated that fuel use increases occurred primarily during the undulating sub-section, and heavy brake and maximum speed violations occurred primarily in the flat sub-section. Fatigued driving becomes less well-planned, resulting in reduced efficiency (e.g. increased fuel consumption) and safety (e.g. braking and speeding violations). Fatigue may manifest differentially depending on track grade. In certain areas, fatigue will cause increased fuel use and economic cost, and in others, reduced safety through driving violations. These factors should be carefully examined in future railway operator research.