Yankee AA1
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Commercial
Flight Crew Last 90 Days 200; Flight Crew Total 1500; Flight Crew Type 250
Communication Breakdown; Situational Awareness
Conflict Ground Conflict; Critical
Flight Crew Took Evasive Action
Environment - Non Weather Related; Human Factors; Procedure
Approximately 5 miles from ZZZ; I announced my position and that I would be entering on a 45 for Runway XX. The frequency was very congested with aircraft in the pattern doing touch and go's. I had my ipad with ADSB input loaded and was able to see the traffic. I entered the traffic pattern on the 45 as planned and was #3 in the pattern; and had all traffic in sight. All traffic (to the best of my knowledge) was announcing every change in position as expected. I announced final on XX; at which time I was #1 to land. The helicopter XXXXX was behind me #2 to land. After touch down I rolled out to the taxiway that is at midpoint of the runway. Just as I made the turn on the runway towards the taxiway I looked left and right; when looking left I seen XXXXX make an evasive maneuver approximately 20 degrees nose high. We could see each others teeth is how close of a call this was. It appears to me that the helicopter landed on the Taxiway instead of the runway and then proceeded to do a take off from the taxiway; however I cannot confirm this as it happened behind me. The helicopter flight school that is at ZZZ uses the taxiway as a runway on a normal basis. They have been spoken to by the FAA in the past about this; and had a FAST meeting about this subject. For the most part while doing hovering training; certain instructors will use the grass area on the East side of the field. This keeps them out of the way of all landing and taxiing traffic and works pretty well. Occasionally they will flight train using the taxiway; which has caused numerous problems in the past and present. I see two issues here: 1)	Helicopters using a taxiway as a runway... staying in ground effect up to approximately 50kts before lifting off. This is an accident waiting to happen. 2)	Multiple flight schools at an uncontrolled field doing touch and go's for hours on end. This makes getting into and out of ZZZ as real problem sometimes when 3-4 aircraft are all doing touch & go's. Would like to see touch and go's limited to weekdays only or not at all.
GA pilot reported a critical ground conflict after landing with a helicopter landing on the taxiway.