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- Creators: Hayden, Carl T.
- Creators: United States. Department of Transportation
In the mid‐1990s, the Arizona Department of Transportation initiated the Maintenance Cost Effectiveness study (SPR 371) with the development of plans and an experiment design to evaluate the effectiveness of a variety of asphalt pavement maintenance treatments. During 1999 and 2001, ADOT oversaw the construction of hundreds of experimental sections throughout the state under the Phase I, Wearing Course Experiment (nine treatments and 82 sections at three sites), and the Phase II, Preventive Maintenance Experiment (24 treatments and 137 sections at four sites). Work continued in 2006 and 2007 under the Evaluation of Maintenance Strategies study (SPR 628) for ADOT with a yearlong program of pavement performance monitoring involving manual pavement distress surveys and automated skid, friction, and surface texture measurements at all the experimental sites. The project culminated with a detailed analysis of key pavement performance data to compare the performance of the individual treatments and determine their overall effectiveness. This report documents the independent findings of both the Phase I and II experiments.
Letter from Carl Hayden to R.P Gilliland regarding the sale of Bright Angel Trail (Ariz.) and construction of the President's Highway from Maine, AZ to the Grand Canyon.
Speech by Carl T. Hayden offering a motion to authorize a road an trail construction program in Grand Canyon National Park "to make these natural wonders accessible to the American people." The speech appears in the Congressional Record, 68th Congress, First Session.
Letter from Carl Hayden to Fred S. Breen regarding Yaki Point, the sale of Bright Angel Trail and the building of a road between Maine and the Grand Canyon.
Letter from Carl T. Hayden to C. H. Gensler, Havasupai Indian Reservation, regarding Hualapai and Cataract Canyons geography.
Letter from Carl Hayden to George Otis Smith asking his advice regarding the mining of asbestos deposits in the Grand Canyon.
Letter from Carl Hayden to L. B. Williams concerning the proposed township in the Grand Canyon.
Letter from Carl Hayden to George W. P. Hunt outlining the proposed national park boundaries and the cost of a township if the state of Arizona decided to acquire one on the rim of the Grand Canyon.
Letter from Carl Hayden to Joseph J. Cotter regarding suggestions on the proposed national park bill.