NY 103 begins at an intersection with NY 5S in Rotterdam Junction, a hamlet in the town of Rotterdam. The highway heads northward as the two-lane Bridge Street, serving a block of homes as it intersects Alexander Drive and Leonard Road.
Starting at an intersection with NY 5S in Rotterdam Junction, a hamlet in the town of Rotterdam, NY 103 becomes two-lane Bridge Street, passing through homes along its route and then intersecting with Alexander Drive and Leonard Road as it heads northward.