TRANSPORTATION
Tip #3 -- Seaports & Airports

Seaports and Airports help your commercial and industrial zones prosper.  Seaports also can allow neighbor deals for importing or exporting garbage.  On the negative side, both create some pollution. Because of their purpose and because they generate pollution, Seaports and Airports should be located towards the edge of your City, and closer to Industrial and Commercial zones than Residential zones.  In fact, residential areas close to seaports or airports will have lower property values.

TIP -- A fully developed Seaport and Airport are worth 5 points on the Judges Scoring (item Transportation #3).  You must have both a Seaport AND and Airport for the full points!

For a Seaport to develop, it must be along a coast or river (obvious).  The elevation of the area must be just one level above the water, so if the shoreline is too steep, you may have to "lower" or "level" the area adjacent to the water for the Seaport to develop.

Seaports must be a minimum of 2x6 tiles, and the water must be at least 4 tiles out.  Because of this, Seaports may not develop along narrow rivers.  Seaports need electricity, water, and road access.  Rail access is also helpful.

Airports must be a minimum of 3x5 tiles.  Airports may not develop if they are too close to Dense Commercial zones because the tall buildings block airplane routes.  Airports need electricity, water, and road access.