  The Effect of Bridge Design on Weight Bearing Capacity  Time
Required Average (6-10 days) Prerequisites None Material
Availability Most items can be obtained locally but may require
visiting multiple stores. Cost Average ($50 - $100) Safety No
issues     The goal of this project is to investigate which type
of bridge has the greatest weight bearing capacity.   Terik Daly
and Andrew Olson, Ph.D., Science Buddies   Share your story with
Science Buddies!   Last edit date: 2013-09-05   There are many
different types of bridges, from simple plank bridges spanning a
small stream to elegant suspension bridges supported by tall
towers and soaring cables. Other bridges are supported with the
structure of the arch, which was used by Roman engineers
thousands of years ago. Yet another bridge type is the truss
bridge, which gets its strength from a framework of triangles
shaped from steel.  Deciding which bridge type to build for a
particular location depends on many factors. What type of
traffic will cross the bridge?