Commonwealth Avenue, Quezon City

Commonwealth Avenue follows a curving route from Elliptical Road to Quirino Highway, which includes the section named Fairview Avenue. The main segment, south of the roundabout with Doña Carmen Street, is characterized by partial control of access, where at-grade intersections are replaced with interchanges and U-turn slots, and pedestrian crossings placed on overpasses (or footbridges). The segment has 18 lanes, with 9 lanes per direction, excluding lanes allocated for buses and jeepneys. Fairview Avenue has 6 to 8 lanes, with 3 to 4 lanes per direction, but intersections are mostly at-grade, usually with traffic lights.

Being located in Quezon City, which has a high number of road accidents, Commonwealth Avenue has a high incidence of accidents along with Quezon Avenue.[4] The number of accidents in the avenue have lend its known nickname, the "Killer Highway".[5]

Commonwealth Avenue in Tandang Sora in 2008, prior to the construction of the Commonwealth Avenue/C-5 Flyover.

The Commonwealth Avenue is divided into two portions, the six-to eight-lane Fairview Avenue and the eighteen-lane Don Mariano Marcos Avenue. The Don Mariano Marcos Avenue, named after Mariano Marcos, the father of President Ferdinand Marcos, was constructed in the late-1960s as a two-lane highway to offer a route towards the Batasang Pambansa Complex. Quezon City was then the capital of the Philippines and embassies were to be put up on the stretch of highway. Because the country's capital was moved back to Manila in 1976, other establishments were put up instead. The Don Mariano Marcos Avenue was later extended from the Elliptical Road to Calle España (now known as España Boulevard). The Don Mariano Marcos Avenue was later renamed into two parts, the Commonwealth Avenue and Quezon Avenue. Later, Commonwealth Avenue regained the eight-lane Fairview Avenue, which ends in the Jordan Plains Subdivision in Novaliches.

In the 1980s, the road was widened into a six-lane highway. During the late 1990s and early 2000s (decade), the avenue was prone to heavy traffic and accidents due to the increase in number of public transportation vehicles plying the highway, and sidewalk vendors crowding onto the road. In the late 2000s (decade), the Metropolitan Manila Development Authority cleared the sidewalk vendors, especially in the Tandang Sora area, which was prone to heavy rush hour traffic. Fairview Avenue uses stoplights and center island splittings in its intersections, while the Don Mariano Marcos Avenue uses interchanges in its intersections.

The avenue is 18 lanes at its widest, and is the widest road in the Philippines, beating the old record set by EDSA.[2]

The entire route is located in Quezon City. The list includes the section of the avenue named "Fairview Avenue". Kilometers are measured from Rizal Park, the Kilometer Zero. 

km[9][10]	mi	Destinations	Notes
12.491	7.762	N170 (Elliptical Road)	Roundabout. Continues to Manila as N170 (Quezon Avenue).
		Masaya Street	Accessible from southbound lanes via U-turn slot. Access to U.P. Village, Teachers Village and Kalayaan Avenue.
12.879– 13.051	8.003– 8.110	N175 (University Avenue)	Accessible from southbound lanes via U-turn slot. Access to University of the Philippines Diliman.
		Central Avenue	Accessible from northbound lanes via U-turn slot. Access to New Era University and Iglesia Ni Cristo Central Temple
		Tandang Sora Avenue	Right turns only. Flyover closed due to MRT Line 7 construction.
		N129 (Luzon Avenue/C-5 Road)
		Zuzuarregui Street	Southern segment has access to Broadcast City
		Holy Spirit Street, Capitol Homes Drive	Holy Spirit Street intersection accessible from northbound lanes via U-turn slot. Capitol Homes Drive intersection accessible from southbound lanes via U-turn slot. Access to Ever Gotesco Commonwealth.
		IBP Road	Accessible from southbound lanes via U-turn slot. Access to Batasang Pambansa on both ends. Access to Payatas Road and the municipality of Rodriguez (Montalban) at the northern end.
20.382– 20.682	12.665– 12.851	Doña Carmen Street	Roundabout. Access to Don Jose Heights. Name change from Commonwealth Avenue to Fairview Avenue. Change from 18-lane road to 6-lane road.
22.041	13.696	Regalado Avenue	Traffic light intersection
23.242	14.442	Regalado Highway	Traffic light intersection. No left turns from southbound lanes. Access to SM City Fairview.
		Mindanao Avenue	Traffic light intersection
25.203	15.660	N127 (Quirino Highway)	Northern terminus.
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Incomplete access