Never ever run your horse on a paved road! Running your horse over a hard surface such as pavement can hurt your horses legs and feet not to mention if your horse is shod he/she could slip and fall and that could seriousely hurt you or the horse because shoes+pavement=slippery. If your horse is properly trained he/she should adamaticaly change leades between barrels. I am not to sure about the sand because i dont really know what the arena dirt is exacaly. I hope i have helped you in some way and i wish you the best of luck!

never run your horse on pavement but the sand thing i would just put it around the barrels just dont make it to deep.