D.915 is a north-to-south state road in northeastern Turkey. The 179 km-long (111 mi) road starts at Of, Trabzon on the coast of the Black Sea branching from D.010 and ends in Aşkale, Erzurum joining D.100 running in a high-elevation mountainous terrain. The route is composed of two parts crossed and overlapped by D.050 on a length of 13 km (8.1 mi) north of Bayburt. The northern part, between Of and Bayburt is 107 km (66 mi) long, and the southern part, between Bayburt and Aşkale is 72 km (45 mi). The northern section ,which is the Derebaşı curves, is considered one of the most dangerous routes in the world.

The route's northern part runs through the districts of Trabzon Dernekpazarı and Çaykara, passes by Uzungöl and crosses Mount Soğanlı of the Karadeniz Mountain Range with the Soğanlı Pass at 2,330 m (7,640 ft) AMSL on the province border Trabzon-Bayburt, and crosses over Çoruh River before joining D.050.

Starting on the junction of D.050 in Bayburt, the southern part of the route runs through Maden, crosses Mount Kop of the Otlukbeli Mountains with the Kop Pass at 2,409 m (7,904 ft) AMSL just south of the province border Bayburt-Erzurum, where a highway tunnel is under construction to ease the route with several hairpin turns. It reaches Aşkale on the D.100 (E80). The route from Bayburt to Aşkale is part of E87.