Logan Canyon
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US-89 LOGAN CANYON Preferred Alternative entire length of this section would be a subject roadway during freezing conditions of the US-89 LOGAN CANYON such a design is not compatible with the of final design; and, the location would be river or other high-water events. Preferred Alternative environmental concerns of the canyon, the evaluated and carefully considered with respect committee had to identify where compromises to impacts on the following highway factors: SECTION IB: This section begins at mp BACKGROUND: US-89 through Logan could be made. Briefly, this resulted in no 387.47 and extends to the end of the Middle Canyon (between Logan and Garden City) has change in the present highway width in the * Roadside drainage channels Canyon Section (at mp 391.6), a length of 4.13 been designated as a Scenic Byway and was first four miles above Right Hand Fork and * Maintenance operations miles. A 34-ft roadway section would be originally constructed in the 1930's. The first numerous other compromises throughout the * Protection of roadside hazards constructed with a design speed of 35 mph. nine miles of the canyon (from Logan to Right remainder of the canyon. The committee felt * Access requirements The maximum degree of curve would be Hand Fork) were widened in the 1960's, and that if the roadway was improved through the * Rolled curb applications for bicycle safety 15°30', and the clear zone requirement would the remaining 28 miles from Right Hand Fork remainder of the canyon, by providing passing be 18 ft. Milepost 387.47 marks the beginning to Garden City have not been improved to lanes, intersection channelization and improved Features of this Section 1A include: of a transition from the 26-ft roadway width of meet current standards. The roadway is very alignment, the existing alignment in the first Section 1A to a 40-ft roadway width of narrow, traversing a steep canyon environment. four miles above Right Hand Fork (the most a. Curve #5 at mp 384 and/or Curve #29 Section 2. For down-canyon traffic, Section Numerous sharp curves limit sight distance and environmentally sensitive area of the canyon) near mp 387 would be flattened if a 3 IB would prepare drivers leaving the 50 mph opportunities to pass. The pavement needs would be acceptable. year accident analysis at the time of design speed of Section 2 for the lower design major rehabilitation and the bridges and other construction shows a concentration of speed in Section 1A. Section IB has been drainage structures are narrow and have PREFERRED ALTERNATIVE: In general the curve related accidents (at either location) defined as an area which could absorb more restricted capacity. Preferred Alternative incorporates elements of in excess of the Statewide accident average roadway widening with less negative effect than the Composite Alternative, but adds additional for arterial roadways. Section 1A. The most recent highway improvement studies detail and/or refinement. Most of the elements of the Preferred Alternative would in Logan Canyon have been in progress for b. Burnt Bridge (mp 385.5) would be Features of Section IB include: the past six years. During this time, input has require amendments to the Forest Plan with replaced with a new structure on the same been sought from federal state and local respect to visual wetland and/or riparian alignment. Structure width would be 2tir ft a. Curve #33 (mp 387.7) would be flattened agencies, concerned organizations and private resources on National Forest Lands. New (approximately 4 ft wider than the $H structures would be protected with parapet by removing rock material and creating a individuals. Considerable time and funding approaching roadway). A detour is new cut. resources have been spent holding numerous walls. Other hazardous locations would be required as the present bridge must be protected with guardrail or other acceptable meetings with interested groups and evaluating entirely removed before a new structure b. Lower Twin Bridge (mp 387.76) would the needs, desires, and potential impacts. In devices. Present parking turnouts would be can be constructed. Vegetation removal improved and new turnouts would be placed be replaced on new alignment November 1990, the draft EIS for this project and river bank modification are required. immediately upstream of the present was circulated and a public hearing was held in recognition of any eliminated turnouts. Additional turnouts which attain at least two bridge, clear-spanning the river. The new in January, 1991. Though some differing c. Roadway elevation would be raised about structure would be 38-ft wide, and the opinions still exist, there is general recognition parking stalls with adequate sight distance would also be considered. Exact locations 3 ft at Logan Cave (mp 386.2), for a total present structure would be removed when that the highway facility needs to be improved length of 1000 ft. The grade elevation the new structure is placed in service. and that those improvements should consider would be determined during final design and in conjunction with USFS recommendations. would allow the roadway to be placed the sensitive beauty of the canyon and its several feet closer to the mountain and environment. The specific elements of the Preferred c. Curve #37 (mp 388.5) would be flattened Alternative are presented below as they pertain somewhat flatten Curve #22. The river by creating a new excavation into the to each section of the project. A map (Figure bank would be protected and revegetated mountain. Design and construction SELECTION OF THE PREFERRED as appropriate. ALTERNATIVE: A committee representing 1) is also provided to help identify the would be similar to Curve #33. the FHWA, UDOT, and USFS was formed to location or improvements. develop the Preferred Alternative by carefully d. A parking area would be constructed for d. Upper Twin Bridge (mp 388.76) would balancing the different and conflicting goals. Logan Cave visitors at mp 386.3 to be replaced with a 38-ft wide structure SECTION 1A This section begins at Right accommodate as many vehicles as The committee gave careful consideration to Hand Fork (mp 383.47) and extends to mp on new alignment, immediately the following: practical. A foot path to the cave would downstream of and about 10 ft higher 387.47, a length of 4.0 miles. Present design be constructed by the USFS in speed, posted speed and existing roadway than the existing bridge The present consultation with UDOT. bridge and roadway would serve as a * Comments received on the draft EIS width of 26 ft would remain unchanged. No features outside the existing roadway would be detour during construction. * Service to the traveling public e. Cottonwood Creek culvert (mp 386.4) * Environmental sensitivity of the canyon disturbed, except as noted below. Portions of would be replaced on the same alignment. e. Curves #39 and #40 (mp 388.8) would * Practicability of construction the section having design speeds lower than the present speed limit would be appropriately be flattened. f. At mp 386.6, the roadway elevation would Since US-89 is classified as a minor arterial, it signed. Placement of concrete curb and gutter, or gutter only, along one or both sides be raised about 3 ft for 500 ft. This f. Temple Fork Road intersection (mp would normally warrant a consistent 50 mph should eliminate occasional flooding of the 389.2) would be improved to provide a design throughout the canyon. However, since of the roadway in portions of or along the Page 1 Page 2 US-89 LOGAN CANYON Preferred Alternative Figure 1 Note: Due to the small scale of this map, curve and / milepost numbers have not been provided. Instead, the / map correlates to text by using the letter that relates to the specific area of improvement for each section of the canyon. (The maps in the final EIS will show the curve and milepost numbers.) Scale In Miles &* \ mL* c €& *«ff**e safer access. Improvements include left Features of Section 2 include: and right turn lanes and new river j. Retaining wall would be constructed t. Uphill passing lane from Garden City crossing. A parking area would be a. A passing lane from mp 391.6 to 393.3 between Beaver Creek and roadway at mp would end at mp 404.6, about 500 ft on constructed and accessed from Temple would be constructed, including pavement 398.1, 398.3, 398.6 and 398.9 to reduce the Cache County side of the Summit. Fork Road in a location currently used as width tapers, a length of 1.7 miles. impact on die creek. Roadway widening Access to Limber Pine Trailhead would parking. The parking area would be made can be obtained by constructing to the be relocated to the Summit (mp 404.75) as large as possible in accordance with b. "Lay down" type fencing would be retaining wall and placing some fill in connection with the existing forest USFS recommendations, without provided in open range area from the material on the east side of the roadway. access road. US-89 would be modified encroaching upon the roadway or the cattle guard near mp 391.6 to the to provide left and right turn lanes. river. Frankhn Basin area near mp 397.2 along k. Vertical rock material (at mp 399.1) which Width transitions are included. both sides of the roadway. Fence design lies within 31 ft of the centerline of the g. Curve #43 (mp 389.4) would be flattened would conform to USFS proposed roadway would be removed. u. Allowance would be made for (moving the highway down hill). recommendations.