A concrete delta between lanes of traffic near the Holland Tunnel entrance does not seem to be the natural place for a picnic plaza, but that didn’t stop the Hudson Square Connection from unfurling lime green umbrellas last month. The neighborhood’s Business Improvement District opened the triangle at Hudson and Broome Sts. in May. Named Freeman Plaza West, the spot is owned and operated by the Port Authority and has been leased to the Connection for 5 years. The BID just west of Soho has spruced it up with trees planted in honor of the Port Authority Police Department’s Holland Tunnel Command workers who died on 9/11, and added summertime umbrellas to shade tables and chairs. The $200,000 plaza is one part of its $27 million, five-year initiative to beautify Hudson Square and make it more pedestrian-friendly.