Please don't be a troll. And please don't make comments about how slow someone else is over a route until you are able to speak from experience on the same roads, conditions, and equippment. And even then, remember that rule about if you don't have anything nice to say? Yeah, practice it.

18mph for a solid 30min on most any road is going to include stops at lights, turns, dealing with traffic, etc. Any experienced cyclist will know these things, and know that an 18mph 'avg' is only achieved by rolling at 20-22mph a fair bit of the time. Put me on an open road out in the middle of no where and yeah, its easier to avg 18+. Put me in the middle of Dallas on a Saturday afternoon and it's a whole different story.