C310 PAX OBSERVES LNDG BE55 PASS IMMEDIATELY TO L OF THEIR ACFT WHILE DECELERATING ON LNDG ROLL. TWR LCL CTLR XMITS; WITHOUT CALL SIGN; 'KEEP TO R.' BOTH ACFT TAKE EVASIVE ACTION.

Narrative

APCHING ARPT FROM THE NE; WE WERE CLRED TO ENTER A MID- FIELD R DOWNWIND FOR RWY 33 AND TOLD TO FOLLOW TFC ON DOWNWIND; EXPECT TO BE #2 FOR LNDG. UPON ENTERING DOWNWIND; ENCOUNTERED REDUCED VISIBILITY DUE TO LIGHT RAIN SHOWER ON S FIELD BOUNDARY. UPON RE-ESTABLISHING VISUAL CONTACT WITH TFC WE WERE FOLLOWING; WE WERE 'CLRED TO LAND #2 RWY 33.' WHILE ON FINAL; SPACING BTWN US AND #1 WAS DIMINISHING. I MADE A REDUCTION IN APCH SPD OVER THE NUMBERS. #1 WAS ON THE TXWY AND CLR OF RWY. ONCE ON THE RWY; WE WERE UNABLE TO MAKE THE FIRST TXWY AND ADVISED TWR 'UNABLE' TO MAKE FIRST EXIT; BUT WILL EXPEDITE TO NEXT EXIT. NEXT RADIO XMISSION WAS 'KEEP IT TO THE R; KEEP IT TO THE R;' AND WITHIN SECONDS A BEECHCRAFT BARON PASSED ON THE RWY OFF OUR L SIDE; WHILE WE WERE STILL ON THE RWY; AND DECELERATING. WE TOOK EVASIVE ACTION TO THE R OF THE RWY AND THE BARON PASSED WITHIN 5 FT OF OUR L WINGTIP. BARON'S EVASIVE ACTION TOOK ITS L MAIN OFF THE RWY AND ONTO THE GRASS; ON THE L SIDE OF THE RWY. TWR NEEDS TO INCREASE SPACING BTWN ARRS IN ORDER TO PREVENT NEAR COLLISIONS. TWR NEVER INSTRUCTED BARON TO GAR; AND BARON NEGLECTED TO GAR.