About 20-minutes north of Meredith, the Holderness School has a pedestrian tunnel, constructed under Route 175 in 2011, so their students and staff can walk from the new dorms and eight outdoor tennis courts to the classroom buildings without having to cross the lightly trafficked road. Have seen riders on bicycles and skate boards using the tunnel, there.
http://www.andrewsconst.com/project/...strian-tunnel/
Maybe a tunnel is a doable improvement for the Meredith traffic hawk signal, pedestrian crossing? Probably, all tunnels have water leaks, so it would need a sump pump or something, to keep it dry.