Transport on the busy Narok-Mai Mahiu road remained paralysed Monday morning after the section that was cut-off last week dipped again.
The Kenya National Highway Authority (KeNHA) said the road sunk in after developing a volcanic fault line.
Motorists plying the route have been advised to seek alternative roads to access their final destinations.
“The Mai Mahiu - Suswa Road section that had on Tuesday been affected by a volcanic fault line has dipped in again, thus cutting off the road for a second time. Heavy commercial vehicles are currently not able to cross the section,” said a statement from the agency.
“KeNHA has embarked on an immediate emergency exercise to restore the section using rockfill. Motorists are requested to bear with the situation, which is expected to necessitate traffic interruption which may last up to four hours as the authority undertakes this exercise within the shortest time possible.”
A section of the road, 6 kilometres from Narok at Suswa developed a fault line Tuesday night stretching 200 metres and completely cutting off the road.
The fault line, according to the agency, was caused by heavy rains that have been pounding various parts of the country in the last three weeks.
This forced KeNHA to close the road and advising motorists in Bomet, Kisii and its environs to use the Nakuru-Erich-Kaplong road.
Road users going to Nairobi from Narok were however advised to use the Narok-Nakuru-Nairobi route.
Engineers from the China Communication Construction Company had repaired the road by last Thursday when it was cut off the first time before it was opened to motorists.