It was possible to select GPS trails in pre-2010 versions of Streets & Trips. When a GPS trail was selected, one could change its color, the thickness, it could be deleted, too, and it was also possible to get the distance information for the entire GPS trail.
These features are now gone. We've gain the ability to import and export GPX files, but we've lost some very useful GPS trail-related functionality, too.
I would also very much welcome to bring these features back, if at all still possible.