Typically, the best toothpick bridges are truss bridges, so you will want to check out the link to the Truss Bridge Laboratory and the Bridge Basics link. The Newton's Apple site is also helpful.

The best way to design your bridge is to first look at the different types of bridges built by engineers today. Bridge engineers try to solve exactly the same problem that you are with your project: Design an attractive structure which optimizes weight and cost. I suggest that you browse around the web and look at the different types of truss bridges that have been built around the world. After you have found some bridges you like, then you can pattern your model after them.

See: http://www.brantacan.co.uk/truss.htm for some excellent theory and examples.

Using quality materials is also very important. Don't use the wimpy toothpicks that you typically find in the grocery store. I have found that the colored cocktail toothpicks are very strong and make for a spiffy looking structure. These are usually found in the picnic or party section of your grocery store.

Good glue is a necessity for strong toothpick structures. I suggest a fast-drying epoxy type glue for maximum strength and workability. Wood glues are also good, but take a long time to set. If you decide to use epoxy, be very careful with it. You don't want to glue yourself or your dog to the furniture . SuperGlues are expensive, do not have good long-term strength and will not give you the best results on porous, wooden sticks.

Best of luck,
rdp

There are some great sections on tips and tricks for handling this project. RC

Good Luck my toothpick bridge building friend,
Alex