Radial Road 8, more commonly referred to as R-8, is a network of roads and bridges that altogether form the eighth radial road of Manila in the Philippines. It runs north-south through northern Metro Manila linking the City of Manila with Quezon City, Caloocan, and Valenzuela into the northern provinces of Bulacan, Pampanga, Tarlac, Pangasinan, and La Union. The portion of R-8 between Guiguinto and Balintawak is also designated a component of the Pan-Philippine Highway network (AH26). It also has a spur segment in Quirino Highway from NLEX to its junction with R-7 at Commonwealth Avenue, both in Quezon City.

The Quirino Highway, formerly called the El Quirino Express Road or Ipo Road, is a four-to-eight lane, secondary highway that connects Quezon City to the municipality of Norzagaray in Bulacan, Philippines. The road is designated as National Route 127 (N127) of the Philippine highway network within the city bounds of Quezon City, Radial Road 7 (R-7), and a spur of Radial Road 8 (R-8) of Metro Manila's arterial road network.