Mass transit advocates are talking up a spur from SEPTA’s Norristown High-Speed Line to King of Prussia. It would start north of the Hughes Park station and connect with a new station between the Court and Plaza at King of Prussia, and possibly another station in the office district on First Avenue. The King of Prussia Business Improvement Group says the rail line to the mall will return six dollars to the local economy for every dollar invested and will make jobs more accessible and employees more reliable. The project was first proposed years ago, but it has been stalled for lack of funding. A study for the rail spur could start as soon as next year, but construction could be as many as 25 years away.