It will take TrackMaker around 20 seconds to
open the Northern England CP file and correspondingly longer to
open the UK CP file.
Once open in TrackMaker make sure 'Show Tracks by Colors'
and 'Tracklog Labels' is ticked in the
View menu.
Now reduce the file size by selective use of the mouse drawing
selection boxes around areas outside your study
area, and then deleting them. Save your new area of interest as
a .gtm file type, as .gtm files containing map data open quicker
in TrackMaker.
If you want the outlines to be a thicker line then select the
whole area with your mouse and click the Change Tracklog Style
the red 'T' icon.
You can use the merge file facility to include your GPS data.
Remember to use the View menu options to untick or tick what you
want to hide or show.