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Home My WebLink About2012-07-18 PACKET 04.P.REQUEST OF CITY COUNCIL ACTION COUNCIL AGENDA MEETING ITEM # DATE 7/18/12 Engineering ORIGINATING DEPARTMENT Jennifer Levitt STAFF AUTHOR COUNCIL ACTION REQUEST Receive information on CSAH 19 and CSAH 20 Intersection. Follow -up to workshop on June 20, 2012. STAFF RECOMMENDATION Receive information on CSAH 19 and CSAH 20 Intersection. Follow -up to workshop on June 20. 2012. BUDGET IMPLICATION BUDGETED AMOUNT ADVISORY COMMISSION ACTION ❑ PLANNING ❑ PUBLIC SAFETY ❑ PUBLIC WORKS ❑ PARKS AND RECREATION ❑ HUMAN SERVICES /RIGHTS ❑ ECONOMIC DEV. AUTHORITY SUPPORTING DOCUMENTS REVIEWED El El El Fj El ACTUAL AMOUNT APPROVED DENIED ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ® MEMO /LETTER: Jacob Gave, July 2, 2012 ❑ RESOLUTION: ❑ ORDINANCE: ❑ ENGINEERING RECOMMENDATION: ❑ LEGAL RECOMMENDATION: ❑ OTHER: ity Administrator ADMINISTRATORS COMMENTS 2A 2 l3 Date COUNCIL ACTION TAKEN: [ ❑ DENIED ❑ OTHER HACOUNCIL FORMS \COUNCIL 2012 \Council 7 -18 -12 \Council Action Form Follow up to CSAH 19 & CSAH intersection.doc Wa4ngton .� unty Public Works Department Donald J. Theisen, P.E. Director Wayne H. Sandberg, P.E. Deputy Director /County Engineer MEMORANDUM Date: July 2, 2012 To: Jennifer Levitt, Cottage Grove Engineer From: Jacob Gave, PE Re: CSAH 19 & CSAH 20 Intersection Jennifer: As a follow up to the City Council Workshop on June 20, 2012, you requested a discussion on the direction of the proposed design for the intersection of CSAH 19 and CSAH 20 as included on the latest layout of the CSAH 19 -20 -22 realignment project and why the County is not proposing to close the western leg of the intersection. Currently, the intersection is a four -way stop controlled intersection. The proposed layout includes closing the eastern leg of CSAH 20 and restricting the intersection such that the only movement that would be prevented at the intersection is the northbound left. The few vehicles that make this movement would instead turn right and then u -turn through the proposed roundabout. This design meets the County goals of the project, specifically the goal of consolidating the two closely spaced full access intersections (CSAH 19 /CSAH 20 and CSAH 19 /CSAH 22) into one full access intersection. At the workshop, the council members in attendance considered an idea that would also close the western leg of the intersection. As you will recall, long -term plans developed by the City in coordination with the County call for the portion of CSAH 20 between CSAH 19 and Jamaica Avenue to be turned back to City jurisdiction while Jamaica Avenue between CSAH 22 and CSAH 20 would become a County road. These jurisdictional changes are currently scheduled for 2016. The project of topic is scheduled for construction next year, 2013. The plans also include a more robust roadway network for the anticipated development in the East Ravine area. The CSAH 19 and CSAH 20 intersection provides an important link in the county highway system. As a county road /county road intersection, this link will be maintained until long -term plans in the area are implemented. On the topic of traffic operations, the project consultant, HDR Engineering, Inc., has prepared a summary of the traffic modeling for current and forecasted volumes on the proposed layout (see 11660 Myeron Road North, Stillwater, Minnesota 55082 -9573 Phone: 651 - 430 -4300 • Fax: 651 - 430 -4350 • TTY: 651- 430 -6246 www.co.washington.mn.us Equal Employment Opportunity / Affirmative Action MEMO — CSAH 19 & CSAH 20 Intersection July 2, 2012 Page 2 of 2 enclosures). The summary states that there are no operational issues anticipated with the design. The modeling indicates that the maximum queue length on southbound CSAH 19 at the roundabout will be approximately 50 feet, happening during the PM peak hour in 2030. The intersections are approximately 1/8 -mile apart. The modeling also indicates that southbound traffic on CSAH 19 will have enough gaps such that the northbound left turn lane is of sufficient length to handle anticipated queue lengths in both AM and PM peak hours in 2030. We look forward to working with you in to implement future plans. Please feel free to contact me if you have any questions or need any clarification. I can be reached at (651) 430 -4316 or 0 acob.gave(a'D-co.washington. m n. us RA22301 \CommunitiesWemo.19 &20 Intersection.docx ONE COMPANY Many Solutions"' �i To: Jacob Gave, Washington County From: Mike Martinez Project: CSAH 19 at CSAH 20 & CSAH 22 cc: Dax Kuhfuss, Steve Jensen, HDR Date: June 25, 2012 Job No: 174267 Re: Queuing at proposed roundabout at CSAH 19 and CSAH 22 The following discusses the results of the operational analysis at the CSAH 19 (Keats Avenue) intersection with CSAH 20 (Military Road) and with CSAH 22 (70 Street), focusing on the anticipated queuing between the intersections of CSAH 20 and CSAH 22, in Cottage Grove, Washington County, Minnesota. HDR conducted an analysis of the proposed intersection alternatives at CSAH 19 and CSAH 20 that compared an all -way stop to a single -lane roundabout. The results of this analysis contributed to the selection of the roundabout as the preferred method of controlling traffic at the intersection. The analysis showed that the in the 2030 design year, the maximum (95 %) queue extending north from this intersection will occur in the afternoon peak hour, and is estimated to be comprised of 1.6 vehicles. Traffic engineers assume that a queued vehicle will occupy twenty -five feet of lane, on average. Rounding up to a full vehicle leads to an anticipated queue length of 50 feet. In the northbound direction, analysis was conducted at the intersection of CSAH 19 ad CSAH 20 using the 2030 design year volumes for the AM and PM peak hours. At this intersection, the northbound and southbound movements are uncontrolled, and all eastbound traffic will be forced south to the intersection with CSAH 22. The three - quarter intersection is expected to operate well under these volumes, with a Level of Service (LOS) expected to be no worse than B. The northbound left turn queues are not expected to spill out of the 290 -foot turn lane in either peak period. HDR Engineering, Inc. 701 Xenia Avenue South, Suite 600 Phone (763) 591 -5400 Page 1 of 1 Minneapolis, MN 55416 Fax(763)591 -5413 wwwhdrinc.con CSAH 19 -20 -22 Intersection Control Evaluation FUTUREYEAR 2030 PEAK HOUR OPERATIONAL ANALYSIS SUMMARY- BUILD CONDITIONS AM Peak Hour • • LOS' C B C D B I B C E I B B C B C Avg. Dela 2 18.8 14.4 22.6 26.5 14.6 14.6 24.6 38.7 14.2 14.2 20.2 14.7 23.4 All -Way Stop Max. ueue 1.9 0.7 4.1 4.5 0.7 1 1.1 4.3 11.7 1 1.2 0.3 2.4 o.8 Approach LOS / Delay'' 2 C / 20.1 C / 21.0 D / 29.3 C / 17.9 LOS A A A A A Avg. Delay 5. 6.4 6.7 4. 6.0 Roundabout Av Queue 6 0.7 0.7 1.3 0.3 Max. Queue 6 1.1 0.9 1.7 0.4 PM Peak Hour East bound Westbound Northbound Southbound Total LOS' C D F D D C F E C C F D F Avg. Dela 2 [ Armroach 24.1 29.7 77.0 26.2 29.6 16.4 81.5 37.2 2o.6 zo.z 85.9 28.7 50.1 All -Way Stop Max. ueue 2.5 4.5 61.7 2.8 3.9 o.6 58.8 7.1 2.1 1.4 84.2 4.3 LOS Delay'' 2 F / 52.2 D / 26.4 F / 53.7 F / 58.0 LOS A A A A A Avg. Delay 5 8.6 5. 6.4 8.2 7.3 Roundabout Avg.Queue 6 2.0 o.6 1.4 1.6 Max. ueue 3.9 o.6 2.0 1.6 1 Level of Service from Synchro Highway Capacity Manual Report L= Left 2 Average delay in seconds from Synchro Highway Capacity Manual Report T= Through 3 Queue length (in vehicles - assumes 25 feet per vehicle) from Synchro R = Right 4 Level of Service from RODEL. Highway Capacity Manual unsignalized thresholds used. 5 Average delay in seconds from RODEL analysis 6 Queue length (in vehicles) from RODEL analysis Appendix hR