NY 40 begins at an intersection with NY 7 (Hoosick Street) just east of the Collar City Bridge in the city of Troy. NY 40 proceeds north along 10th Street for less than a block, turning northeast along Oakwood Avenue, a two-lane mixed commercial and residential street through the Frear Park section of Troy. Passing the campus of St. Mary's Hospital, the route begins to run along the western edges of the namesake park, reaching an entrance at a junction with Frear Park Road. Running along the western edge of Wright Lake, the route turns northward and soon leaves the western extremities of the park. Now back in the North Central section of Troy, NY 40 runs north through Oakwood Cemetery.