The Nairobi Expressway mother company, Moja Expressway has explained why there was heavy traffic on the road on Thursday.
In a statement on Thursday evening, Moja Expressway said it was a result of flooding.
It further said that water from Mombasa Road had affected movement on two lanes of the Expressway.
Moja Expressway also issued a warning to motorists to exercise caution as they drive on the road.
"The section of the road has experienced significant flooding due to surface runoff and rainwater from the adjacent Mombasa road affecting movement on 2 lanes.
"Please be advised that due to heavy rain experienced in Nairobi, motorists using the Nairobi Expressway between JKIA Entrance Toll Station and the Eastern Bypass Entrance A Toll Station are cautioned to slow down due to flooding," Moja Expressway said.
On Thursday, motorists using the Expressway towards the Mlolongo experienced heavy traffic due to the rains.
Motorists using Mombasa Road were also not spared as water filled at Imara Daima junction and outside the Imaara Mall.
The heavy rains have rendered several roads in the city estates impassable since they began.
The government has warned motorists not to drive through flooded roads as they endanger their lives and those of the people onboard.
Since the onset of the floods, so far 210 people have lost their lives while 90 are still missing.
A total of 33,100 households have been displaced affecting approximately 165,500 people.
