6.3.- 6.6. SR 02-09-2004 - Laserfiche WebLink

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Ms. McPherson Page Three January 22, 2004 recommendations refer to. As we all are aware, there are weekend and special day situations in the City of Elk River that are substantially worse. This needs to be kept in mind as the traffic portion of this project is reviewed. In an attempt to help to understand Level of Service (LOS), I have had our traffic engineer prepare a layman's summary describing different levels of service as follows: Level of Service (LOS) is a letter designation used by traffic professionals to describe a range of operating conditions for a particular roadway or intersection. Levels of Service range from "A" (free-flow conditions) to "F" (gridlock). Typically, LOS is based on vehicular delay, traffic volume, speed and/or roadway capacity. Within the Twin Cities area, LOS conditions are considered acceptable between Level of Service "A" and Levels of Service "C to D". LOS C to D define conditions where traffic is increasing and will not allow one to pass, or conditions at a signalized intersection where not all the vehicles are able to get through the green light on a single cycle. City staff has recently met with staff of Mn/DOT District 3 to discuss future improvements to TH 169. The City Council wants Mn/DOT to take their study of TH 169 to the next level, which would include environmental documentation and geometric layouts. Mn/DOT staff has indicated in our meeting that they would like to study an area along TH 169 from TH 10 to Princeton. They believe that it will take the remainder of this year to arrive at a scope of services, hire an outside consultant, and negotiate a fee and timetable. Once the project is initiated, Mn/DOT expects that the Environmental Impact Statement and the geometric layout along with significant amount of public participation meetings would take a minimum of two years. Therefore, we cannot expect to have any definitive answers relative to Mn/DOT planned improvements along TH 169 until sometime in late 2006. Storm Drainage We have reviewed the storm drainage calculations prepared by Schoell and Madson. Calculations we reviewed were revised based on our first set of comments and a meeting with their engineers. Basically, the drainage concept uses two interconnected ponds with no outlet {the west and south ponds), which will hold back-to-back 100-year rainfall events and one pond (the easterly pond), which outlets under TH 169 at the pre-development rate. The few comments we still have relative to this revised drainage calculations are as follows: · The design relies on infiltration rates from the ponds with no outlets. We are still waiting for soil borings and an analysis Of the actual infiltration rates versus the assumed rates in the drainage calculations. · The south pond contours show a 3:1 slope. City requirements are that a minimum 4:1 slope be above and below the normal water level of the pond or the pond must be fenced. The grading plan should be revised to reflect a 4:1 slope. Ltr-O12104-McPherson Howard R, Green Company CONSULTING ENGINEERS