On The Underground: Promos -

"ON THE UNDERGROUND: ENGINEERING CREW PROMO - Hire crews of engineers that can help build track when you most need them, or plan ahead to create branch lines! Setup: Place on engineering crew tile per player next to the board and return the extras to the box. Gameplay: A player may spend one of their actions to take an engineering crew tile. Each player may hold at most 1 of these tiles. It may be spend to take a branch tile or place a track token. Doing so does not cost an action. NOTE: This promo / nano-expansion requires a copy of any On the Underground edition.

Clear obstructions that perpetually plague underground transportation systems and gain points! Setup: Before setting up the game, randomly draw three destination cards and place an obstruction tile in each of the stations they show. Shuffle those cards back into the deck. Gameplay: A player must pay 2 branch tiles to connect a line to a station with an obstruction tile. That player then scores three points and removes the obstruction tile from the game. 

Visit the city's vibrant street fairs and earn points when you connect them to where the Passenger started! Setup: Before setting up the game, randomly draw 3 Destination cards, and place a Street Fair tile in each of the stations they show. Shuffle those cards back in the deck. Gameplay: When placing Track tokens, a player scores 2 points whenever they connect a station with a Street Fair tile with the Passenger start station using the same line.