Draw a history of roads taken that follows the roads. Google Map API ANDROID

Question

This is my current map and what I want. We see in blue the current lines drawn, and in red those expected. I want the user's trips to follow the road and not get out. I have no clue on how to proceed. And feel free to give some advice on the user's locations data storage in database to make a " history road taken". Thanks!

     mMap = googleMap;
     ArrayList<LatLng> coordList = new ArrayList<LatLng>();
coordList.add(new LatLng(XXXXXXXX, XXXXXXXX));
        coordList.add(new LatLng(XXXXXXXX, XXXXXXXX));
        coordList.add(new LatLng(XXXXXXXX, XXXXXXXX));
        coordList.add(new LatLng(XXXXXXXX, XXXXXXXX));
        coordList.add(new LatLng(XXXXXXXX, XXXXXXXX));
        coordList.add(new LatLng(XXXXXXXX, XXXXXXXX));
        coordList.add(new LatLng(XXXXXXXX, XXXXXXXX));
        Polyline line = mMap.addPolyline(new PolylineOptions()
                .addAll(coordList)
                .width(10)
                .color(Color.BLUE));