Kenya Urban Roads Authority has issued a public warning that some roads in Nairobi and Kiambu are partially impassible.
KURA on Wednesday said the roads in the two counties have been affected by the ongoing heavy rains.
"Following the heavy rains experienced last night across the country, the following roads within Nairobi and Kiambu Counties have been heavily affected leading to partial closure," KURA said.
Kura said Enterprise Road, Eastern Bypass and Thika Bypass have been badly affected.
"The traffic police and our technical team are on the ground to direct traffic and enhance the safety of Motorists," the roads authority said.
Kura said it shall keep Kenyans updated as the situation unfolds.
The authority urged motorists to drive safely and avoid attempts to cross flooded sections.
Many people have been stranded after Thika Road flooded Wednesday morning at Kenyatta University and Juja.
Traffic flow along the Thika Super Highway has been affected after a section of the highway was submerged by water, particularly the Thika bound on the underpass of the Juja Flyover area.
Motorists are using Service Lane to access the highway past the High Point area.
Also submerged are Traffic Police Offices within Juja Police Station.
Police are said to have turned away motorists on both sides of the road to avert a tragedy.
Police have appealed to motorists to exercise due caution when using the Juja Super Highway.
Motor vehicles from Nairobi heading towards Thika are making u-turns and coming back to the Githurai roundabout.
No motor vehicle is heading to Nairobi because floods have cut off Kahawa Sukari.
Traffic officers are on the ground diverting motorists towards Mwihoko Road to join the Eastern bypass and to 44 Road towards Kahawa West so that they can proceed to Thika.
Githurai and Mwiki areas have also been affected after they experienced heavy rains during the night.
It was still raining Wednesday morning.
The service lane from Kasarani towards Githurai at the Car Wash area has been affected by floods too.