Works on four bypasses — Eastern, Western, Northern and Southern— are to be completed in three months and ready for use in January 2022.
"Traffic jams will end in Nairobi. You are going to see an entirely different city," Transport CS for Transport James Macharia said.
“By constructing these roads we have a complete Nairobi circuit around the city. You can now go around Nairobi without passing through the city centre," he said during a tour on Wednesday last week.
"This will end traffic jams caused by motorists using the city centre to get to the other side of Nairobi."
Nairobi traffic jams are estimated to cost the Kenyan economy Sh100 billion every year, or about Sh11 million per hour.
Faster road transport will open up the city and attract more investors, meaning a better economy and more jobs for young people.
The 52km Eastern bypass starts at City Cabanas along Mombasa Road, linking motorists through Ruai towards Ruiru and passing over Thika Road to Ruaka where it joins the Northern Bypass.
The Nairobi Eastern Bypass dualling project was among 11 major infrastructure projects Kenya showcased to international investors during the Belt and Road forum in Beijing, China, in May 2017.
CS Macharia said dualling the 16km Western Bypass will be completed by the end of the year.
"If you are coming from the Thika side, you come through Muthaiga, through Red Hill, you join this road at Ruaka and then can go towards the west without having to go through the city.
The 15.3km road will pass through several towns, Gitaru, Wangige, Ndenderu and Ruaka. This is the fourth and final ring road in the Nairobi Ring Road Network Masterplan.
Works also include construction of 17.31km service roads and construction of seven grade interchanges at Gitaru, Lower Kabete, Wangige, Kihara, Ndenderu, Rumenye and Ruaka.
President Uhuru Kenyatta is expected to commission the completed project.
The roads are his commitment to leave a capital city without traffic congestion, Macharia said
"We are doing a lot of work, more than we expected to have done by this time. In almost every part of Nairobi, you will find roads being constructed," Macharia said.
We are doing this to make Nairobi a better place. This is one city where we host big offices," he said.
State House Chief of Staff Nzioka Waita described the Northern Bypass as as a major infrastructure project to create a regional business hub.
The 31-km bypass starts from Ruaka Trading Centre along Limuru Road, overpasses Banana Road through Runda and Thome estates.
It then goes to Kahawa West and eventually to Ruiru, through Kamae, where it joins the Eastern Bypass.
China's Sinohydro Limited in January 2018 signed a contract for dualling the Nairobi Northern Bypass
The China Road and Bridge Corp constructed the Nairobi Southern Bypass, which was completed in 2016.
The 28.6km bypass dual carriageway begins at the southern edge along Nairobi-Mombasa Road, passes through Gitaru in the northern part of the town and connects to the Western Bypass.
The chief of staff said the Kenya Urban Roads Authority has also constructed about 300km of roads in small towns and estates in Nairobi
"Cumulatively all these roads and pedestrian walkaways will ease Nairobi's congestion in the near-term as the city gears up for mass transit solutions like commuter rail and bus rapid transport,"Waita added.
(Edited by V. Graham)