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Home My WebLink AboutDepartment of Commerce - 8th AvMontana DeJ~artment of Transportation J~m Lynch, D~rector 2701 Prospec! Avenue Brian Schweitzer, Governor PO Box 20 I001 Helena MT 59620-I001 December 8, 2006 Mr. Kenneth E. Olson, Jr. Mayor of Laurel 814 5th Ave. Laurel, MT 59044-1906 Subject: STPU 6905 (1) 8th Ave. ~ Main to 7th -Laurel CN 3927 Dear Mayor Olson: Attached is a letter from Engineering Inc. that discusses the potential costs and benefits of modifying the current project design. This topic was discussed at the Plan-in-Hand held in November. A narrower and lower roadway typical section was analyzed by the Consultant and summarized in the Design Modifications Memorandum. The proposed project benefits and associated engineering fees are summarized in the letter. Although this project is managed through the Department of Transportation, this project uses Urban funds and therefore requires your input on this potential design change. Please review the letter and provide a response at your earliest convenience. We will not proceed until we receive a reply from the City. Thank you for your attention to this project issue. Please feel free to contact Mark Studt at 444-9191 if you have any questions. TJC :mis 2927_Mayor. DOC copies: Copies with all Tom Martin P.E., Consultant Design Engineer Brace H. Barrett., District Administrator - Billings Steve Klotz, Laurel Public Works Director Bryan Vieth, Design Supervisor, Consultant Plans Section Consultant Design Project File Consultant Design Bureau An Equal Opporlunity Employer Phone: (406) 444-6200 Engineering Division Fax: (406) 444-6253 TTY. (800) 335-7592 Web Page: www, mdt mt.gov November 14, 2006 Mr. Mark Studt, PE Consultant Design Bureau Montana Department of Transportation P. O. Box 201001 Helena MT 59620-1001 Reforence: Design Moditleations Memorandum 8th Avenue - Main to 9th - Laurel STPU 6905 (2) Control No. 3927 E.I. No. 99137 Dear Mark: As discussed at the Plan-in-Hand (PIH) conducted on November 2, 2006, Engineering, Inc. was given the task of determining the cost and benefits, if any, that could be realized by lowering the proposed roadway profile and reducing the proposed street and boulevard widths from the current design to a narrower footprint. This narrowing was suggested during PIH and would include narrower travel lanes, parking lanes, and boulevard widths. The option for lowering the roadway evolved when a Montana Department of Transportation (MDT) comment surfaced during the Scope of Work Report review pea'iod, which requested that the asphalt thickness in the typical section be increased from 90 mm to 120 mm and MDT's new structural coefficients be incorporated. The result was that the overall thickness of the surfacing section was reduced by 240 mm (9 inches). Since conception, the roadway grades have been driven largely by the need to provide vertical separation between the proposed road surface and the proposed storm drain trunkline which caused the proposed finished surface of the roadway to be elevated higher than the existing roadway. This resulted in fill slopes, impacts to personal property, nuroe~ous construction permits, and the need to reconstruct portions of driveways, private sidewalks, fencing, and other items. Benefits that can be realized from lowering the roadway and narrowing the footprint include radueing the fill slope depths and widths, a reduction in the number of construction permits, providing more area adjacent to the right-of-way (R/W) for utility placement, and a reduction in impacts to existing features such as fencing and landscaping. This will also help us with reducing the area of R/W needed between 2nd and 4th Streets West where R/W acquisition is necessary for this project. 1300Norll~1~ohslechW~y' Billings.~l 591C'2' Pl~one(406)6~6-5255' Fax(406)656-0967' ww'.,,'e,ginccom Mt'. Mark Studt, PE November 14, 2006 Page 2 Below is an itemized list of cost savings and project benefits that could be realized by lowering the roadway profile and by narrowing certain typical section dimensions. Cost Savings: Based on discussion at tile Plan-in-Hand meeting conducted November 2, 2006, for the project, we analyzed the effects of reducing the roadway typical section fi`om its current hack-of-curb to back-of-curb width of 16.0 m to 12.3 m. We have calculated that the savings would be approximately $140,650.00 (difference between attached estimates). This savings is due to reduced typical section surfacing quantities, as well as reduced storm drain inlet piping lengths. A noticeable savings will be realized by decreasing the amount of reconstruction of private sidewalks and driveways. We estimate that the quantity ofcenerete estimated for these features ceuld be reduced by approximately 380 sq m ~ $59.75/sq m (current estimate) = $22,722.93. Adding the contingencies, ere. fi`om above raises this to approximately $34,400.00. In addition to these construction cost savings, we have estimated the savings in R/W. We estimated that there will be 16 fewer construction permits (per R/W Plans...Lots I l, 12, 13, 15, 23, 25, 26, 31, 32, 33, 34, 36, 38). At $500.00 per construction permit (estimate, based on $300.00 minimum per Brent McCaan), this would be another $8,000.00 savings. The R/W requirement between West 2nd Street and West 4th Street on the west side of 8th Avenue could be reduced by an estimated 440 sq meters (4,735 sq feet) for an estimated cost savings of perhaps $10,000.00 (average of around $2.00/sq f~ based on ad. jaeent lot pficea). Additional savings in RFC/could be realized by avoiding having to replace trees, landscaping features, sprinkler heads, etc.. that would be damaged and require replacement due to new sidewalk installation under current design. The associated cost savings is estimated at $2,500.00. The original project cost for fencing was approximately $45,000.00, including all the contingencies. We estimate that the cost would by reduced by approximately $7,500.00, since less existing fencing would be directly impacted by construction. Mr. Mark Studt, PE November 14, 2006 Page 3 Pl~oiect Benefits: Engineering, Inc. looked at the utility conflicts, primarily power poles, and underground utilities that might lie near the existing R/W line. It does appear that several utility poles and some of the fiber optics will no longer be in conflict iftha roadway is narrowed near the south end oftha project, but a cost savings was not assessed due to the unknowns. Narrowing up the typical section would provide more mom between the R/W limits and the back of sidewalk for utilities to oecapy. We have taken a quick look at the effect of decreasing the imparvious surface by narrowing the roadway, and it appears that it has a relatively insignificant effect on the overall design peak flow; it is estimated that a reduction of approximately 2.5 cfs can be realized by reducing the asphalt width of 8th Avenue. This reduction would be beneficial to the project, since it allows the design to incorporate more free-board (distance from top of water surface at maximum design elevation to top of basin berms) in the detention ponds by allowing an increase in the allowable outfloTM from the upstream detention basins as they are currently designed. Therefore, it is not anticipated that the reduced width will create the need for smaller trunkline pipe, but narrowing the roadway still does have a net project benefit in terms of hydraulic design. En~ineerina Fees: We have assessed the design efibrts to pursue both lowering the roadway and narrowing the roadway, and estimate our design services would approximate $70,000.00 or so. Most of the work remaining for this project is still within Engineering, Ine.'s scope of work and is, therefore, not included as part of fha $70,000.00. The estimate is only for those eft-offs to lower and narrow the roadway from the current design. Summary The net effect of lowering the roadway profile and reducing the roadway typical section dimensions is an estimated $133,000.00 savings (construction costs + RfC/+ incidentals - design services) to the project, Supporting documentation is provided to this memorandum as attachments. Sincerely, /f Kirk Spalfling, Pmj~'ct Manager /dml encl Montana Department of Transportation Page ~ F~ Preliminary Estimate Project 'Ri{e: 8th Avenue - Mair~ Io 9th - Laurel Prepared by: Kirk Spalding PreJact Number, STPU 6905(2) Dale: September 22, 2006 PmJecl Lenglh: 1,08 km Locallon: Yelrowslona Co~'~' Des. Super Approval: Type er'Work: , Project Cord Number:. 3927 D A Approval: eU~UUUUL3~' 838 I:ENCE'CHA1N UNKst~btolaT bi $40.00 $21.S20.0~ $gI~20.00 PmJ~ Len,q~h IAVera~e Prelect Finish Top Wtdtll m Cost per ~]lameler Uses Ca~lan T~ 106 Montana Department of Transportation B~ pm=., Preliminary Estimate Jan0$-Jul06 Projec~TIf~e: Prepared by: T. Kelsey Project Numbec Date: November 6, 2006 Project Lenglh: Location: Laurol- Yellowstone County Des Super Approval: Type of Work: Subject: Ori___glnal Typical QuanUties D A Approval: Page 1 of I ~mDun ~ Unit Prices ~ll',i'(~Us~ [Paih]3527Ealimate Smeller Typical Seclion xls Bid Prices JanOS.JulO$ Montana Department of Transportation Preliminary Estimate Project Title: Prepared by: T. Kelsey Project Number. Date: November 6, 2006 Project Length: Localion: Laurel - Yellowstone County Des Super Approval: Type o[ Work: Subject: Smaller Typical Quanti~/Chang~ D A Approval: Page I of 1