I-85 and I-40 remain joined as they continue eastward to the Research Triangle region, anchored by the cities of Chapel Hill, Durham, and Raleigh. West of Durham near Hillsborough, the two highways split, with I-40 heading southeast through Chapel Hill, Durham, and Raleigh while I-85 continues eastward through Durham, then northeastward as it exits the city. In between Greensboro and Durham, I-85/I-40 is eight lanes wide even through the more suburban stretches.
I-85 and I-40 remain linked as they extend eastward to the Research Triangle region, anchored by Chapel Hill, Durham, and Raleigh. West of Durham near Hillsborough, these highways separate; I-40 heads southeast through Chapel Hill, Durham, and Raleigh, while I-85 continues eastward through Durham before turning northeast. In between Greensboro and Durham, I-85/I-40 has eight lanes even in suburban areas.