limits imposed by the ISTEA freeze (and the ISTEA Shelby exemption) that are the Federal GVW limits of influence. What Minnesota would do with the authority to relax the 80,000-pound GVW limit on its Interstate highways in not known. To date, Minnesota has elected to maintain an 80,000-pound GVW limit (or less) on all highways in the State.
Bridge Formula B: Except for North Dakota, the five western border States apply Bridge Formula B on all highways. North Dakota applies the provisions of the formula on Interstate highways, but ignores inner bridge requirements and allows 48,000-pound tridems on non- Interstate highways. Given no Federally-imposed Bridge Formula B, North Dakota might choose to extend its bridge formula policy to Interstate highways. The other four States would probably proceed cautiously concerning liberalizing Bridge Formula B provisions, particularly given that they have these provisions on the rest of their road network without being obliged to do so by Federal law.
ISTEA Freeze on GVWs: The GVW freeze of ISTEA applies to the operation of combinations involving a truck tractor and two or more cargo-carrying units on Interstate highways. The GVW levels incorporated in the freeze in these five border States is the same as the GVW limits these States used for many years prior to the freeze.
From the western border crossing standpoint, only three of the 54 western border crossings are directly affected by the weight aspect of the ISTEA freeze. These are the crossings for Interstate Routes I-5, I-15, and I-29. In the case of I-15, the Canadian RTAC GVW limit of 137,800 pounds is already allowed by the ISTEA from the Canadian border to Shelby, Montana. The GVW limit on all but these three crossings are under State authority.
ISTEA Freeze on Lengths: The “box-length” freeze of ISTEA applies to the operation of combinations with two or more cargo units operating on the NN. The length limits incorporated in the freeze in these five border States is the same as the length limits these States used for many years prior to the freeze. From the Canadian perspective, none of these ISTEA cargo-carrying length limits would be viewed as particularly restrictive. From the western border crossing standpoint, twenty of the 28 western border crossings of interest are actually directly affected by the length aspect of the ISTEA freeze, including those for I-5, I-15, and I-29.
One potentially positive effect of eliminating the ISTEA freeze by devolution to the States would be facilitating WASHTO efforts to achieve improved uniformity in regional TS&W regulations as these relate to cargo-carrying length limits on NN highways.
What would happen to western border trucking if Federal size provisions were applied to non-NN highways on the NHS? This would have little or no effect. These size provisions, exclusive of the ISTEA freeze, are minimums and are already surpassed by the western States more or less throughout their networks.
What would happen to western border trucking if Federal weight provisions including grandfather authority was applied to non-IS highways on the NHS in conjunction with the above size provisions? The major impact of this would be associated with the application of the