1. How do you raise roads into Highways?

Build the highway, make sure it is long. Then build a road over it. Just drag and the road will form. Now use the ramp and put it next to the road so that it is touching the road and the highway. It will go blue if in the right place. Four squares are needed to form the ramp. You don't really need highways because they are expensive, takes up lots of room and no one actuall uses them.

Lay a train track and then drag a road over it and then cars can cross the track. Train tracks won't go over rivers, the subway will go underneath. All you have to do is use the tool that connects train tracks and subways. Subway is better for people because they don't take up any room, put them beside important buildings and tourist places. Train tracks are good for trade. Both can go upto the border for trade and to get people to visit your city.

To build a bridge start a road about five squares from the water, drag it over the water and then another five squares on the other side. It will say do you want to build a bridge, say yes. If it says can't be built due to other buildings then demolish those buildings or make it somewhere else.