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HomeMy WebLinkAboutBLOOM - PHASE 1 - PDP210014 - SUBMITTAL DOCUMENTS - ROUND 3 - VARIANCE REQUEST (3)6162 S. Willow Drive, Suite 320 Greenwood Village, CO 80111 303.770.8884 • GallowayUS.com Memorandum Page 1 of 3 To:Engineering Department City of Fort Collins 281 N College Ave Fort Collins, CO 80524 From:Brian Horan, P.E. Galloway Date:January 19, 2022 Re:Bloom MTIS Supplement – International Boulevard/Greenfields Drive Intersection Control Type – Roundabout Variance Galloway, on behalf of Hartford Homes and in support of the Bloom project currently under review, is providing the following written justification for the future intersection control of the proposed Greenfields Drive/International Boulevard per the request of the City of Fort Collins. This memorandum should be considered a supplement to the Master Traffic Impact Study (MTIS) supporting the Bloom project. During the course of review, it was determined a formal request for the ultimate intersection control of Greenfields Drive/International Boulevard, which will be constructed with the first filings of the Bloom project, would be necessary. The intent of this memorandum is to satisfy that request. The City of Fort Collins Master Street Plan (MSP) provides a map of the long range roadway and intersection vision for the City. The MSP primarily provides context for arterial and collector roadways and the general locations for connections to each. Specific to this project, International Boulevard and Greenfields Drive are both shown as “Arterial 2 Lanes” and their intersection is designated as “Potential Roundabout”. The MSP provides the following note: “Potential Roundabout Locations shown are those identified as good candidates in terms of need and feasibility. Prior to implementation, each location will be evaluated on a case by case basis.” The MTIS for Bloom provides an operational and queueing analysis for this intersection to provide information in determining the ultimate control at this location. It should be noted that the conventional intersection was determined acceptable from an operation and queueing perspective in the MTIS. The following justification for the ultimate configuration of the subject intersection is provided in the format suggested by the Larimer County Urban Area Street Standard (LCUASS) section 1.9.4 – Variances and Appeals Processes. Although the request is not a variance from a particular standard, the format of the request is formatted to fit the section. a) Identifying Issue. Identification of the standard to be waived or varied and why the standard is unfeasible or is not in the public interest. As mentioned above, the subject future intersection is designated as a “Potential Roundabout” in the MSP. This memorandum is the formal request to construct this intersection as a conventional intersection and preclude the construction of a roundabout. 1-19-22 Bloom Roundabout Variance 1/19/2022 Galloway & Company, Inc. Page 2 of 3 The intersection will operate more safely and effectively as a conventional STOP control and future signal, if warranted. This location was likely selected because of the intersection of two Arterials. Roundabouts perform well in areas where traffic volumes from all legs are similar in scale. As detailed later in this memorandum, this intersection will see uneven traffic volumes at all legs. Although the classification for both roadways is an Arterial, they will function more as collectors providing conveyance to Mulberry Street and Vine Drive. As the character of these roads change due to development occurring a roundabout will be fixed and unable to react to change. The conventional intersection is more easily adaptable to geometric changes or signalization if warranted while still maintaining safe and effective conveyance of vehicles, pedestrians, and cyclists. b) Proposing Alternate Design. Identification of the proposed alternative design or construction criteria. It is the intent of the developer to construct a conventional intersection at this location. As detailed in the MTIS the intersection will function acceptably as a STOP controlled intersection for the foreseeable future. The MTIS identified that in the long range future the intersection will likely NOT meet signal warrants and acceptable levels of service would be expected via STOP control. In the case that the STOP control starts to perform at capacity the option to build a signal is available. The conventional intersection control type allows for a phasing, if you will, of control type and improvements as development and area connections does or does not occur. Roundabouts perform well when all legs of the roundabout are expected to have similar volumes. The eastern leg of the intersection will likely never experience significant traffic volumes as it serves a limited scoped of development that is land locked by rail to the north and development to the east. The northern leg of the intersection will see lower volumes in the short range before the rail crossing is achieved. The western leg of the intersection, International Boulevard, will see increasing volumes as development occurs and when or if International Boulevard extends to Timberline Road. These often “uneven” volumes at a roundabout will cause it to perform poorly from an operation standpoint. The conventional intersection will support phased development in the short term and potential signalization in the future if necessary, although it is unlikely to be warranted with the current planning level information available as detailed in the MTIS. Understanding that the STOP controlled intersection would perform adequately as detailed by the MTIS the following is provided within the U.S. Department of Transportation (USDOT) Federal Highway Administration’s (FHWA) – Roundabouts: An Informational Guide regarding capacity comparisons between roundabouts and Two-Way Stop Controlled (TWSC) intersections: “A roundabout is unlikely to offer better performance in terms of lower overall delays than TWSC at intersections with minor movements (including cross street entry and major street left turns) that are not experiencing, nor predicted to experience, operational problems under TWSC.” Additional guidance is provided in the document that describes the subject intersection. “problems experienced by low-volume cross street traffic at TWSC intersections with heavy through volumes on the major street are very difficult to solve by any traffic control measure. Roundabouts are Bloom Roundabout Variance 1/19/2022 Galloway & Company, Inc. Page 3 of 3 generally not the solution to this type of problem because they create a significant impediment to the major movements. This situation is typical of a residential street intersection with a major arterial.” In this example the “residential street” is the eastern leg of the subject intersection that will likely always experience low volumes. The conventional intersection control will likely provide more operational benefit to the intersection over the lifetime of the intersection. c) Comparing to Standards. A thorough description of the variance request including impact on capital and maintenance requirements, costs, and how the new design compares to the standard. The MSP recognizes the need to evaluate roundabouts that are identified. This has been provided in the MTIS for the overall Bloom project. Generally speaking, roundabouts will have higher landscaping maintenance costs and land area needs. While the intersection is STOP controlled the conventional intersection type will cost less and require less maintenance. Generally speaking, similar upfront costs are expected with signalization as compared to a roundabout although signalization may never be warranted. The conventional STOP controlled intersection is less burden from a land and maintenance standpoint for the City. d) Justification. The Professional Engineer must determine and state that the variance will not be detrimental to the public health, safety, and welfare, will not reduce design life of the improvement nor cause the Local Entity additional maintenance costs. The proposed plan (as varied) must advance the public purpose of the standard sought to be varied equally well or better than would compliance with such standard. It is the opinion of Galloway and the development team that a conventional intersection at International Boulevard and Greenfields Drive will adequately and better serve the public and the City. As a STOP controlled intersection it will safely and effectively convey vehicles and pedestrian movement in the near term scenarios. The “standard” roundabout may operate poorly with certain legs experiencing much lower volumes than the others. The conventional intersection would provide the same or better opportunities for pedestrian and bicycle movement throughout the area. The proposed intersection control type will not be detrimental to the public health, safety, and welfare of the community and will likely be less maintenance cost for the City of Fort Collins. The control type will equally or better convey vehicles, pedestrians, and cyclists through the area. Thank you for consideration of the information contained herein. If you have any questions or would like additional information, please contact me at brianhoran@gallowayus.com or 970- 800-3300.