On 04.12.2021 at around 05:50 hrs AIP subcontractor (RNTC) vacuum tanker bearing Reg#6490 YS was travelling from HMPS to AIP camp with partially filled jet cleaned oily water. At approx. 4 kms away from HMPS, the road diversion (damaged section of road due to cyclone Mekunu in 2018) area, the tanker drove straight instead of following diversion and landed into the existing dry wadi. Why it happened/Finding : Vehicle’s electrical system malfunctioned causing the lights to go off few seconds prior to the incident; this caused distraction of driver focus from the road. Physical barriers and signs to warn vehicles approaching towards the damaged road section were not adequate. Temporary road diversion provided is not signposted to guide the road users; no physical measures (eg: signs, lighting, speed breaker, flashing lights) to slow down the approaching vehicles (only sign board, 350 m before the incident location indicating road speed as 80 kmph). The damaged road section (eroded by wadi flooding during 2018 Cyclone Mekhnu) remained uncorrected till date exposing the road users to this hazard.