I know I've talked about this before on another thread, but I can't find it. So, hopefully this is the right place for such a topic.
Problem: Drawing large structures for bridges is impossible and the designer is forced to use smaller pieces which might not look too good.
Solution: Using a larger tile size is quite common for large vehicles, like airplanes and ships, but rarely, if ever, used for way objects. This is a demonstration of the possibility of using a larger tile size for bridges. It's one bridge, but uses two different sets for each end so that it's easy to distinguish.

pak, dat and png file of above demo:
http://dl.dropbox.com/u/17111233/128_192_test_bridge.rarJust load it in any pak128 pakset.
P.S. I've only built it for the two positions shown above, so the ramps are very wrong.
Theoretically, for every 25% increase in size from the base tile size, you can add one tile to the length.
For example, using 128:
pak160 = 3 tile length in pak128
pak192 = 4 tile length in pak128 (as shown)
pak256 = 6 tile length in pak128
Some known issues:
- It only looks good if the player uses the length the bridge was designed for. Maximum length is easy enough to set, but there is no such thing as minimum length.
- No spans can be used without some serious graphical bugs
- Pillars become well hidden
- Might not work if a stop is used on top of it
- Sliced underground mode looks odd
- Objects underneath might show through, because technically, the deck is invisible.