Agenda - Public Works Committee - 09/21/2004

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TRAFFIC CONCERN' AT 169TM AVENUE AND NEON STREET By: Steven J Jankowski, City Engineer CASE Background: The City has received a request from the resident at 5866 169th Avenue NW to address a problem at the intersection of Neon Street and 169th Avenue. This intersection is actually a right angle bend in the roadway where 169th Avenue transforms into Neon Street. The resident lives on the outside corner of this bend and has experienced numerous instances of vehicles sliding off the street and into his yard. Attached to this case is an aerial photoH'aph illustrating the area. The radius of the street bend is approximately 95 feet and does appear to have a slight super'elevation (banking of the crowe which permits a faster safe speed). A safe travel speed for a curve having this radius would be 20 miles per hour. There are currently no warning sigaas advising motorists of this bend. Alternatives .Considered: The safe travel speed could be increased by increasing the radius of the curve, however, the proximity of this intersection to the intersection of 169th Avenue and TH 47 limits the ability to increase this radius to a design speed of 25 miles per hour or less. Increasing the radius to accommodate this desiH2 speed would require the acquisition of approximately 0.1.5 acres of additional fight of way fi-om the property on the northwest corner of the intersection and the reconstruction of about 340 feet of roadway. A second alternative to increasing the safe speed at this bend would be to increase the superelevation of the existing road way to the maximum permitted limit of 6 percent. Currently the superelevation appears to be about 2 percent. This alternative would require the reconstruction of about 150 feet of roadway at an estimated cost ranging between $15,000 and $20,000. Additionally it should be noted that reconstruction of this section of roadway would need to be carefully implemented since it is the sole access .som'ce tbr the entire neighborhood to the east. A temporary roadway may need to be considered as a part of the reconstruction plan. Although there may be a number of vehicles leaving the roadway at this location, a review of the accident history shows no incidents reported to the police department in the past five years. This is not unusual for accidents which involve inconvenience more than injury or property damage. The lack of accident reports limit the ability to analyze the reason ibr the accident, however, it might be that motorist are caught by surprise by the bend. This could be particularly true if the accidents are occurring after dark since there is not a street light m the vicinity of the intersection.