Contributions to spacetime are welcome, and will be considered for inclusion. Below are suggestions for what is needed short term.
Contributions needed: a generalize method for Track (and Tracks, and TracksCollection)
generalize(t, timeInterval = "5 minutes")
generalizes track t into 5 minute intervals; result is a Track (...) where the sp slot now is a SpatialLines object, and time and endTime reflect start and endtime of the segment.
generalize(t, distance = 1000)
generalizes the track into 1000 (distance units, usually m)
generalize(t, n = 20)
generalizes the track into segments, each having 20 points
generalize(t, ..., tol = 55)
simplifies the SpatialLines object using rgeos::gSimplify(SL, tol = 55)
generalize(t, ..., toPoints = TRUE)
does not generalize to SpatialLines, but keeps a point (the middle point) of the set over which we generalized.