The road is a standard eight-lane controlled-access highway; the total cost of the expansion was estimated at Ksh 27 billion (US$ 330,000,000), but was higher due to increasing fuel costs. The highway was completed in February 2012. The section between Muthaiga roundabout and Ruiru town will also be a part of the Nairobi Northern Bypass that will link to Limuru Road.
Thika road (A2) is part of the major road network in Kenya classified as A. This road links Nairobi to Ethiopia border town of Moyale contrary to the belief by many that it only links Nairobi to Thika.
- "Highway set for completion by year end" Daily Nation, March 3, 2011
- "Cost of road to go up over fuel prices" Daily Nation, May 12, 2011
- Nairobi By-passes Receive 8.5 Billion Office of Public Communications, January 29, 2008
- "Thika Road may need Sh5b more" The Standard, May 12, 2011
- "China gives Kenya Sh8.5 billion for Nairobi bypasses" Kenya Engineer, January 30, 2008