The railway system consists of several major sections: ; Mombasa–Nairobi Section This section, measuring , is known as the
Mombasa–Nairobi Standard Gauge Railway, and connects the port city of
Mombasa and
Nairobi, the capital and largest city of Kenya. ; Nairobi–Naivasha Section This section was also contracted to the company that constructed the Mombasa–Nairobi Section. The line stretches from Nairobi to
Naivasha, a distance of about , at cost of
KSh. 150 billion (US$1.5 billion), borrowed from the China Export-Import Bank. Construction began in 2018 and the line was officially opened for passenger train service in October 2019. International freight for neighbouring countries interchanges at the Naivasha Inland Container Depot. ; Naivasha–Kisumu Section This section, measuring , stretching from
Naivasha to
Kisumu, on the eastern shores of
Lake Victoria, is contracted to
China Communications Construction Company, at a budgeted cost of KSh. 380 billion (US$3.8 billion), borrowed from China Exim Bank. Loan papers between Kenya and China were scheduled for signatures in September 2018, but were deferred until a commercial viability study is conducted on the entire Mombasa–Kisumu railway. ; Kisumu–Malaba Section This section, measuring approximately , takes the SGR line to the town of
Malaba, at the international border with Uganda. CCCC, is the contractor for this section as well. The contract price for this section is about KSh. 169 billion (US$1.69 billion). The price for the Naivasha–Kisumu–Malaba section is KSh. 549 billion (US$5.49 billion) and includes the laying of railway tracks in both sections, dredging and expansion of the port of Kisumu, and the expansion and modernization of the inland container depot at
Embakasi, in Nairobi. ; Lamu–Lokichar-Nakodok Section This railway line, totaling , is a component of the
Lamu Port and Lamu-Southern Sudan-Ethiopia Transport Corridor (LAPSSET) development project. Under the LAPSSET plan, this line would be extended to
Juba in South Sudan. ; Nairobi–Moyale Section This section also falls under the LAPSSET program. It extends from Nairobi to Moyale, at the international border with Kenya's northern neighbor. It is planned to be extended to
Addis Ababa, the capital city of Ethiopia. In January 2024, Kenya Railways Corporation estimated the cost for this section at Ksh835.5 billion (US$5.57 billion), with the link from Nairobi to Isiolo costing Ksh358.8 billion (US$2.392 billion) and the remaining stretch to Moyale costing Ksh476.7 billion (US$3.178 billion). ; Naivasha–Lokichar Section This proposed railway link, measuring an estimated , would link the two main standard gauge railway systems in Kenya; the Mombasa–Malaba SGR System and the Lamu–Nakodok SGR System. ==Purpose, history, and operations==