\draw[ultra thick] (1,13) to [out=180, in=180] (1,14);
\draw[ultra thick] (3,14) to [out=360, in=360] (3,13);
\draw[ultra thick] (1,13) -- (3,13);
\draw[ultra thick] (1,14) -- (3,14);
\node at (2,13.5){START};