Hill intervals are the closest thing I do to speed work. I do repeats on the steepest parts and this simulates speed work without risking injury. I try to do this workout once a week. It is the hardest and most intense workout I do. I tend to walk down the steepest slope then run up it as fast as I can. The repeats consist of approximately 100 yards of a very steep climb then a level ridge out and back to the steep part. I walk down and then run up it again.
This routine generally helps with hills and general speed work. Since I only run 3 days a week I have to combine workouts. I run a tempo on the roads and a long run on crushed gravel trails.