Minutes - Public Works Committee - 06/15/2004

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this intersection as ultimately having traffic signals. MnDOT has control over TH 47 and has held firm to their position that traffic signals will only be installed subsequent to the intersection meeting one of the eight possible technical signal warrants. When the Highway 47 improvement project was being designed, the City's engineering consultant SRF Inc. had prepared a signal justification report for this intersection which concluded that signal justification warrants had been met. However, this report utilized as an element of its justification traffic which was exiting through the Rivers Bend Plaza onto CR 116. This traffic was not actually utilizing 142nd Avenue, but was visually observed and recorded, and projections were made as if this traffic were using 142nd Avenue as it should have been. The SRFjustification study was rejected by MnDot, which argued that once a signalized intersection at Xkimo Street was installed and operating there would be less traffic using 142nd Avenue. A subsequent signal justification study was performed by SRF at the City's direction based upon traffic counts taken in late April 2001. The Xkimo Street connection to TH 47 had been functioning since December 2000 at the time of this study. The results of this second study showed the traffic volumes using 142nd Avenue had decreased over those identified in SRF's earlier study. The City has not requested MnDDT to do another traffic signal warrant study since that time. City Engineer Jankowski advised the City might wish to consider encouraging MnDDT to pursue the following modifications to this intersection: 1. Extend center median through 142nd Avenue This modification would result in the safest condition possible at this intersection since it would eliminate all conflicting turning movements. This change would also have a severe impact to the River's Bend Plaza which is still acclimating to the median closure on CR 116. 2. Pursue signalization of the intersection This modification could provide the opportunity for protected left turning movements from TH 47 and would allow controlled access from 142nd Avenue. The negative aspects of this modification could include additional congestion on TH 47, and delayed access from TH 47 onto 142nd Avenue, particularly at off peak hours. 3. Restrict left turning movements onto TH 47 This was one safety consideration suggested for consideration by the design engineers at the time of the 2000 TH 47 project plan preparation. This modification would utilize concrete islands which would allow left turns from TH 47 onto 142nd Avenue, but would prevent left turns from 142nd Avenue onto TH 47. Left turning movements from a side street onto a major roadway are considered more hazardous than the reverse movement. This modification would not affect the ability to get into Rivers Bend Plaza. City Engineer Jankowski indicated staff recommends obtaining additional infomiation prior to the City making a request for an intersection modification to MnDDT. The City should request a traffic signal warrant study be performed by MnDDT to determine whether signalization of this intersection is a viable option. Secondly, the City should request MnDOT analyze how left turns Public Works Committee/June 15,2004 Page 6 of17