Request for Additional Stop Signs at the Intersection of 163rd Ave / Marble St

Staff has received a request for additional stop signs at the intersection of 163rd Ave and Marble street. Currently there are stop signs on the Marble St portions of the intersections. The requested action would change this intersection to an all stop condition. The reasons given for requesting the additional stop signs are excessive speed and poor visibility at the intersection when traveling west bound on 163rd Ave.  Both the letter requesting the stop signs and the neighborhood petition are attached to this case.  Photos of the intersection will be presented at the meeting.

10-15 minutes

The following information was gathered at the intersection:
Traffic count on north Marble St-57
Traffic count on south Marble St-30
Traffic count on 163rd Ave east of Marble St-203
Traffic count on 163rd Ave west of Marble St-173
Posted speed limit at intersection-30 mph
85th percentile speed-40.8 mph
Accident data from 2012-2017- 2 minor accidents none involving pedestrians

The traffic counts and accident history do not meet warrants to change this to a 4 way stop condition.  There is a visibility issue on 163rd Ave caused by the vertical rise to the intersection, but if you are stopped at either leg of Marble St you can see down 163rd Ave in either direction. Staff would recommend cutting back vegetation in the NW corner of the intersection to help improve visibility.  Staff requested that the police department set up their radar trailer to collect speed data on 163rd Ave on two separate days 10/3 and 10/4 , so we could get an accurate reading of vehicle speed in the area.   The data showed a range of speeds from 8-50 mph with the 85 percentile being 40.84 mph.

Funding for any additional signage would come from the general fund.

Staff recommends not  installing additional stop signs at this intersection based on the traffic counts and accident history.  Staff would also recommend that the Police Department continue to enforce the 30 mph speed limit in the area in an effort to reduce speeds on 163rd Ave.

Motion to accept staff recommendation to not install additional stop signs at this intersection based on the traffic counts and accident history  or reject staff recommendation and approve alternative motion based on committee discussion.