Nema is seeking public views on the plan to expand the Northern and Eastern bypasses to dual carriageways.
The environmental agency yesterday gave the public until June 24, to submit their comments on the Environmental Impact Assessment Study (EIAS) report for the proposed dualling.
"The construction of the Northern and Eastern bypass has greatly transformed and expanded the city environs and many jobs and businesses along the road," Nema and Kenya Urban Roads Authority said yesterday in a public notice.
The dualling of the Northern and Eastern bypasses is estimated to cost Sh30 billion.
Kura said there are many encroachments and illegal structures that must be removed to pave the way for construction to start.
The Northern Bypass will be expanded to an eight-lane superhighway. It was constructed by China Road and Bridge Corporation.
The Northern Bypass starts from Ruaraka to Ruiru where it joins the Eastern Bypass. The Northern Bypass will also help motorists to access Waiyaki Way and the Nairobi—Nakuru road without going through the city centre.
The Eastern Bypass starts from Mombasa Road through Cabanas, Pipeline, Njiru and Thika Road onwards.
The Eastern Bypass that was started in 2013 is approximately 32km. It is expected to ease traffic jam on the key road that links motorists from the busy Jomo Kenyatta International Airport and Mombasa-Nairobi highway to Thika Superhighway.
Nema said the two roads will have service lanes, new roads done in highly developed locations, overpasses and underpasses, footbridges and paths. The notice also indicates that matatu bus stages will be put in place.
In 2018, the Kenyan government contracted Sinohydro Limited to convert the Northern bypass to a four-lane dual carriageway with culverts, drainage channels and walkways on both sides.
