HomeMy WebLinkAbout13.1 Deviation Request - 100 ft straight approach 1091 Stoneridge Drive • Bozeman, Montana • Phone (406) 587-1115 • Fax (406) 587-9768
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Civil/Structural Engineering and Surveying
September 1, 2020 Griffin Nielsen
City of Bozeman
Engineering Department 20 E. Olive Street Bozeman, MT 59718
RE: Norton East Ranch Subdivision – Phase 5, Deviation Request from COB Design
Standards and Specifications Policy – Table IV-2 – Length of Tangent at Intersection for Local Roads must be 100’ (161141) Dear Griffin,
This letter is to provide a deviation request from the tangent length standards listed in the COB Design Standards and Specifications Policy – Table IV-2 for the project referenced above. Pursuant to Table IV-2, the applicant is requesting a deviation from the 100’ tangent requirement
for the following intersections as it relates to the development proposal for the Norton East Ranch
Subdivision, Phase 5: 1. Boomtown Road and Laurel Parkway 2. South Reliance Avenue and Gooseberry Drive
3. Westgate Avenue and Gooseberry Drive
The applicant is requesting this deviation due to the presence of the Covenant of Dedication encompassing the existing wetlands. This Covenant of Dedication (Doc. No. 2299907) was filed in 2008 and restricts any development from occurring within the perimeter of the covenant area.
Because of this, the road alignments required additional horizontal curves to avoid encroaching
into this area. The addition of these curves made the 100’ tangent approach requirement outlined in the City of Bozeman DSSP extremely difficult to maintain while providing a desirable road layout with equal block lengths. The 100’ tangents were maintained in all areas where practical, but the three intersections named above would require a large redesign of the subdivision in order
to accommodate the 100’ tangent approach.
Additionally, all local roads within Norton Ranch Subdivision, Phase 5 will be 25 MPH roads (15 MPH adjacent to Parks). This slow speed limit will allow for vehicles to safely navigate all turns and intersections without any line of sight or stopping speed issues. All horizontal curves meet the
standard of a minimum centerline radius of 150’ which allows for vehicles to view oncoming
traffic without any visual impairments.