Transport Tycoon Deluxe is sort of like the expansion to Transport Tycoon although it is standalone.
It is built on the same engine, but there are several bug fixes, additions, etc.
For instance: There are now more vehicles/aircraft/ships/trains and all of the names have been altered. Factories and other second-stage industry (manufacturing as opposed to mining/harvesting/etc) no longer have production limits. But most importantly there's a better version of an old construction option for trains:
Traffic lights. They tell a train that it can/can not go forward because there is/is not another train on the tracks. It prevents messy explosions and allows you to have high-traffic stations (3 or 4 or 10 or 12 or, heck, 50 trains sharing 1 track each way).
The way it's better than the original Transport Tycoon lights is that, in the original, they could only be built on straight sections of track (As opposed to diagonal), and they could not be one-directional. Also, they used to be uglier.
The way it works is this: you build one track going each way, and then you build one-way lamps on each side. So only eastbound trains use the eastbound track and only westbound trains use the westbound track. It works beautifully.
Other than that, it's a lot like Transport Tycoon. If you really need more information, go there.