The GOP solution is to increase borrowing for transportation projects by about $700 million per year. But to avoid overtaxing the STF, Republicans would pay off that extra debt from the state’s General Fund. The problem with that, said Rep. Roland Lemar, D-New Haven, a Transportation Committee co-chair, is the General Fund can’t spare the room on its own credit card. Its borrowing is used to build schools, upgrade universities and wastewater treatment plants, preserve open space and farmland, and support economic development.