State Police say Interstate 95 in Augusta was shut down on the northbound side as police dealt with a man sitting alone inside a car with a gun. The incident was on the off ramp at exit 113 in Augusta, and State and Augusta Police are on scene.    Northbound Interstate traffic was diverted at exit 112 ( Civic Center Dr. )  and motorists traveling north had to use secondary roads to get back on the Interstate at Sidney.  Southbound Interstate traffic was not effected.  The situation resolved around 8:30 a.m. No further details are being released at this time.