The Extended-Weight Coal Haul Road System, created by Kentucky's Legislature in 1986, consists of all roads which carry over 50,000 tons of coal in a calendar year. Trucks hauling coal on this system are authorized to exceed normal weight limits through the payment of an annual decal fee. A research study was initiated in July of 1992 to analyze the impacts of the extended-weight system. This interim report, prepared after one year of a three-year study, describes the analyses performed thus far and presents preliminary findings, recommendations, and a discussion of future work.

Analyses in this report are based on: historical data on coal production and transportation: data from coal decal applications; interviews of legislators, transportation official, coal company representatives, and coal trucking representatives: newspaper articles; vehicle classification data; a pavement cost analysis; and accident data.

Preliminary conclusions include: 1) The extended-weight system has apparently been somewhat successful in accomplishing its primary objectives: to enhance the competitiveness and economic viability of Kentucky's coal industry and to eliminate the perceived need for coal haulers to violate the law in order to be competitive; 2) Overall accident rates are no higher on the extended-weight system than on other comparable routes, but the fatal accident data is significantly higher on the extended- weight system; 3) The coal-decal fee structure results in a net annual loss in Road Fund revenue of approximately $2 trillion; 4) Forty percent of the revenue from data sales is allocated to the counties, although less than ten percent of the extended-weight system is county-maintained; 5) The heavier weights of coal-decal trucks add approximately $9 million annually to pavement overlay costs and increase other highway costs to an (as yet) undetermined extant; 6) Road users throughout the state are subsidizing the movement of Kentucky coal by underwriting the increased costs of maintaining and improving the infrastructure.

The following preliminary recommendations ware developed: 1) Route geometry and cross section should be considered when deciding which routes will be included in the extended-weight system; 2) The selection of routes for the extended-weight system should include consideration of system connectivity; 3) Countermeasures should be evaluated and implemented to alleviate the braking problem for heavy trucks approaching signalized intersections; 4) A revision to the allocation of Energy Recovery Road Fund dollars should be considered to more accurately reflect the composition of the extended-weight system.

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The contents of this resort reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Cabinet, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation.