761—181.1 (321) Statewide standard.
	 181.1(1) A local authority may issue a special permit, based on this rule, allowing the operation over a bridge within its jurisdiction of a fence-line feeder, grain cart, tank wagon or tracked implement of husbandry with a weight in excess of the weights allowed under Iowa Code chapter 321.
	 181.1(2) A local authority shall evaluate a bridge according to section 6 of the American Association of State and Highway Transportation Officials (AASHTO) Manual for Condition Evaluation of Bridges, Second Edition (2000), as revised by the 2001 Interim Revisions. The operating level shall be used for the evaluation of the bridge with only one fence-line feeder, grain cart, tank wagon or tracked implement of husbandry on the bridge at a time. The live load to be used in the analysis for permit decisions should be the actual vehicle crossing the bridge, together with an impact factor in accordance with section 3 of the AASHTO Standard Specifications for Highway Bridges, Sixteenth Edition (1996), as revised by the 1997, 1998, 1999 and 2000 Interim Revisions.
	 181.1(3) A local authority is not liable for damage to any vehicle operating within the terms of a permit the local authority issues under this rule, or to the vehicle’s cargo, if the local authority imposes weight limits on a bridge specified in the permit subsequent to the issuance of the permit. The weight limits are effective when signs giving notice of the limits are erected.
	 181.1(4) The AASHTO publications may be ordered from the Web site www.transportation.org. They may be inspected at the department’s office of bridges and structures.
This rule is intended to implement Iowa Code sections 321.1, 321.463(4) and 321.471.