First of: This mod does almost the same as Mauvebic's "Nodebox utility" mod http://minetest.net/forum/viewtopic.php?id=2750
I saw it too late and had my Mod finished when I found it :-(
Most of the things in my mod are more or less the same as in Mauvebics. What you get additionally are crafting receipes, a large bridge (spans 3 nodes!), and a bridge that builds itself automaticly.
License: GPLv3
Download: https://github.com/Sokomine/bridges/zipball/master
Browse code: https://github.com/Sokomine/bridges
The large bridge (spans 3 nodes):
After placing the auto-bridge node (looks like the top of a chest from all sides), the rest of the bridge gets built automaticly. Leftover parts can be found in the chest-like node:
The auto bridge after the deploy-node-chest has been replaced manually with a groundplate (sand and torches not included!):
Some bridge parts forming a simple bridge:
What T-Junction, end-part and corners are good for:
Crafting receipes:
Groundplate, can be used as is or as the basis for bridge parts:

Handrail, basic part:

A small bridge:

Middle part of a bridge, for use between e.g. small bridges:

Corner part:

A T-junction:

If your bridge has to end in midair:

A handrail:
Handrail, two sides (for the top of stairs):

Handrail, three sides closed:

The 3-node-wide large bridge:

The self-building automatic bridge:
