In all a great expansion to a great game.
The new transportation additions are great like avenues which are just two one way roadsput together which can also be a start/end of a highway.One way roads are in as too are monorails, cruise ships, ferries -they might have been in the first i cant remmber though.
Thats not all, you can drive/fly/float around your city! You control your transport using a weird control system (that may need some getting used to) from a birds eye view. These can be done in free roam or for money as missions. Not all missions are for money i should add some give you rewards and some give you credibilty. There are really two kinds of missions good and evil. As you can probably tell the evil ones generally give you alot of money (say around 20,000 simoleans) but you lose favour as a mayor. The good ones generally give you credibility and maybe a few thousand simoleans if your lucky. You earn the money or whatever by driving/flying or whatever around your city, some missions are short and have smaller rewards and the longer ones with more stops along the way which give you more.
So basically if your cities broke and your out of loans you can do afew of these which replenish over time and you can maintain your funds that way.
In all a great expansion to a great game.