Route 15 is 79 kilometres (49 mi) long and is in the southeastern corner of the province of New Brunswick.

Starting at the north end of the Petitcodiac River Causeway, it loops around the city of Moncton on Wheeler Boulevard, then turns northeast from Dieppe to Shediac.

From there, it turns east and bypasses Cap-Pelé crossing the Scoudouc River, then southeast to meet the Trans-Canada Highway at Port Elgin.

Its construction was controversial, with critics alleging that it was only built to give Moncton-area politicians better access to their summer cottages in the Shediac area[citation needed].

A two-lane bypass of Shediac itself was built shortly afterward.