2017-05-10 CC Packet - Laserfiche WebLink

Home Browse Search

-A SEH Building a Better World for All of Us® October 12, 2015 Ms. Jane Rose Traffic Engineering Manager Anoka County Highway Department 1440 Bunker Lake Boulevard NW Andover, Minnesota 55304 Dear Jane: RE: Anoka County, Minnesota CSAR 14 at CSAR 54 Signal System Flashing Yellow Arrow Considerations SEH No. ANOKC 122928 As requested, we reviewed the intersection of CSAR 14 (Main Street) and CSAH 54 (201s Avenue North) in the Cities of Centerville and Lino Lakes with regards to proposed modification of the existing intersection traffic signal left turn operations. Recently, the County has received requests from the public to have flashing yellow arrow operation installed and activated at this intersection. In response to these requests, the County had SEH perform an analysis of the intersection to determine if flashing yellow arrow operation can be utilized here. The analysis would include review of the feasibility, cost, and safety of the intersection for flashing yellow arrow operations. Following is the results of our analysis. This 4 -legged intersection was first signalized in 2007, with protected left turn phasing installed for all approaches. The posted speed limit on CSAH 14 is 45 mph, while the north leg of CSAH 54 is posted at 55 mph and the south leg of CSAH 54 is posted at 50 mph. All iptersection approaches have a single separate dedicated left turn lane, except that the southbound CSAH 54 approach has a dual left tum lane. The County provided SEH with limited turning movement traffic count information (completed for 9:30- 11:00 am on April 8, 2007). However, we had concerns about the traffic volumes shown on this count summary for this time of day given local development and typical area traffic patterns, as well as the age of the count itself. The southbound CSAR 54 left and right turning traffic volumes for 10:00-11:00 am were much higher than would be anticipated for this area. To address these concerns, SEH performed an AM and PM peak hour traffic count during the week of October 5-9, 2015. An AM peak hour traffic count was taken on Wednesday, October 7, 2015 between 7:00-8:00 am while a PM peak hour traffic count was taken on Monday, October 5, 2015 between 4:00-5:00 pm. As shown on the attached count summary, current peak hour traffic volumes were much lower for all movements to and from the north (eastbound left turns, westbound right turns, and all southbound movements) than shown on the 2007 count. For our analysis of the intersection, we utilized the 2015 counts but also will mention the 2007 count in our review. SEH also obtained crash data for the intersection for the most recent 3 years of available crash data (2012- 2014) from the State's crash website. SEH then completed a brief field review of the signal system to confirm that the existing traffic signal plans correspond to the current installation of the signal system and take into account , the current intersection geometrics. SEH also reviewed traffic signal cabinet Engineers I Architects I Planners I Scientists .Short Elliott Hendrickson Inc., 3535 Vadnais Center Drive, St. Paul&MN.55110-5196 SEN is 100% employee -owned I sehinc.com I 651.490.2000 I 800.325.2055 � �r •8$8.908.8166 fax 123