You need at least 150 points, including bonuses, to unlock this achievement. This is easily done with a partner on LIVE, or in a local match with two controllers.
When you start, choose 8 destination cards, preferably all on one half of the map (Duluth marks the midpoint, so try to stay on one side or the other as much as possible.) Your partner will take the minimum and every turn will choose just one destination card until he runs out and then switch to drawing railway cards. Once you have 8 destination cards, focus on drawing railroad cards, always drawing two face down cards until you have 60 cards. Once you have enough cards, start placing railways, focusing on connecting as many destination cards as you can. At the end of the game you should have between 220-300 points, easily earning this achievement.
The achievement will unlock after the final scores are displayed.