With a GPS running watch, any road, path, or trail can be the perfect place to run your next speed session.  I live near a quiet sidestreet that is about a mile long and doesn’t have many houses.  This is perfect for my intervals and repeats.
You will no longer need to rely on the track for these workouts as you can set the watch for specific distances and see how far you have gone. For example, I will often run a half mile interval followed by a timed recovery. The Garmin Forerunner can be set to beep as your interval begins and then again as you hit the half mile mark. I especially enjoy that the watch logs the time and distance so that I can look back on my workout results.
With the Garmin giving accurate distances, any type of speed work that was previously measured and timed on the track can now be done anywhere.