In addition to his work in municipal politics, he was elected to the departmental council of Finistère in 1901, becoming president of the council in 1912. He worked hard to obtain government funding for major transport links and for improvements at the (strategically important) Port of Brest. In 1922 he mandated the first studies for a possible bridge to provide a direct connection from Plougastel-Daoulas to Brest, crossing over the Élorn estuary. Work on the bridge started in 1926. Louppe did not live to see it completed, but when it was opened to traffic in 1930 the bridge was nevertheless named after him.
