Overpasses can be dragged from the draggable section of your inventory onto an intersection that has exactly four connections. An overpass changes the existing intersection into two crossing roads without any interaction between the traffic.
Bulldozers are used to permanently remove neighborhoods from the map. The neighborhood must not be the only one of its kind. The neighborhood will be permanently destroyed.
Freeways are upgraded roads. Freeways move vehicles twice as fast as simple roads. You can use freeway tiles to cause vehicles to route around neighborhoods and prevent those neighborhoods from being clogged with through traffic.
