Coffee Break Training: Access and Water Supplies: Road Bridge Carrying Capacities [open pdf - 153KB]
"Today's picture illustrates a common problem found in suburban and rural environments: access road bridges that are not capable of supporting the imposed weight of fire apparatus. Depending upon the fire code adopted in the jurisdiction, fire apparatus access roads may be required for new buildings or facilities. In the model fire codes, National Fire Protection Association (NFPA) 1, Fire Code, requires that access roads reach within 50 feet (15 meters (m)) of an exterior door that provides access to the interior of the building. The 'International Fire Code'® requires access roads to reach within 150 feet (45 m) of all portions of the facility or first floor exterior wall of a building. Both require that bridges or elevated surfaces provide the ability to support the weight of fire apparatus. When specifying weight-carrying capacities, remember to include automatic or mutual-aid apparatus that may have to use the bridge."
Coffee Break Training - Fire Protection Series No. FP-2012-41
United States Fire Administration: http://www.usfa.fema.gov/