Top Guard Truncated Domes for FDOT E1P39 W.D.4 John Ringling Causeway March 21, 2017 Posted by on March 21, 2017March 1, 2018 Top Guard black truncated domes installed +/-360 sq.ft. along John Ringling Causeway in Sarasota (Sarasota County). FDOT contract E1P39 W.D.4. Roadway Concepts is prime.