The one from Rich2001 led me to this: http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr84.pdf
Which was perfect for what I was looking for. Thanks for all the help to both of you!
Ok, I'm not an engineer, but I need the help of one. I need to build a bridge of wooden material to span 30' and carry a moving load of 10,000. I can use 10x10 beams as the pilings. Can anyone help with what type of span between the pilings and the thickness of the cross beams and deck...