Rehabilitation work started Tuesday on the historic stone arch bridge that carries Limekiln Pike over the Little Neshaminy Creek in Montgomery and Horsham Townships. Northbound traffic has been detoured around it for about two years, with a five-ton weight restriction, because of severe structural deterioration.  PennDot says crews will rebuild the walls and deck, reinforce the foundation and install new guide rails, and it’s closed during construction.  The project should be finished in about five months at a cost of just under $1 million.