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three seconds from a car traveling 39 mph to 10 seconds for vehicles traveling well under the limit. Mr. Jankowski stated it is significant to note the different reaction times associated with the same speeds. This is explained by the fact that many motorists slow down when they observe a potential conflict, such as a parked vehicle or pedestrian or child. On the other hand, the vehicle traveling 39 mph, blatantly in excess of the speed limit, did very little to modify its speed, leaving a very short reaction interval. Mr. Jankowski continued that the Traffic Review Committee, consisting of Director of Public Works Dean Kapler, Police Chief David Gustafson and City Engineer Steve Jankowski, observed the site together on April 14. The Committee observed the visibility of Tungsten Street from both the intersection of 142nd lane and the driveway at 14270 Tungsten. With a City vehicle traveling a near constant speed of 30 mph, a reaction time was noted of between seven to nine seconds at both the intersection and the driveway. A reaction time of 10 or more seconds is considered desirable. In reviewing the accident history for the intersection, there have been none reported to the Police Department for the years 1993 through 1997. A review of the speed study indicates that some speeding over the posted limit is occurring. When evaluating speeds, traffic engineers define the speeds at which 85% of the traffic is traveling as a safe and prudent speed. The speed survey shows that the 85th percentile speed of northbound traffic is 31.6 mph, while that of the southbound traffic is 28 mph. Ten percent of the traffic is traveling at a speed more than two miles per hour over the speed limit. Mr. Jankowski summarized the warrant criteria for the placement of an all-way stop which is as follows: (1) Traffic signals are warranted but cannot be immediately installed. This is not the case in this location. (2) An accident problem of five or more accidents corrected by a stop sign in a 12-month period. This warrant is also not met. (3) Minimum traffic volumes of 500 vehicles through the intersection in an hour for eight hours of the day. This intersection had 51 vehicles per hour during the period of 4:30 p.m. to 6:00 p.m. The existing volumes do not warrant an all-way stop. The posting of stop signs on one or two legs of this intersection may be warranted "where a combination of high speed, restricted view, and serious accident record indicates a need for stop control". Mr. Jankowski noted that there is a somewhat restricted sight distance to the south, although more than 90% of the time, there is between five to ten seconds of reaction time at the driveway at 14270. He acknowledged that, in the winter, the sight distance may be less on the approach from 142nd Lane due to snow. Mr. Jankowski explained that it would seem logical if a stop sign were to be posted, that it be posted for northbound Tungsten Street. However, that would give left turning 142nd Lane traffic the fight-of-way over northbound Tungsten traffic. This is not the normal rule of fight-of-way and will cause confusion. To eliminate that confusion, a stop sign could also be posted. Staff has made the following findings: (1) There have been no accidents at this intersection in the last five years. (2) The speeds of the majority of the traffic is reasonably close to the posted limit. (3) Blatant speeding, more than five miles per hour over the limit, is minimal. (4) Sight distance, during non snow periods, is limited and allows less reaction time than desired. (5) The intersection contains a school bus stop on the east side. Based upon these findings, the Traffic Committee recommends posting stop signs to control northbound Tungsten and eastbound 142nd Lane. Toni Schrier, who lives across from Tracy Kremer's home, stated that 142nd has only been a street for two years. It was not all the way up to Sunfish Lake Boulevard before so there wouldn't have been a problem there before the two years. Looking at the traffic study, maybe most of the speeds on the low end were by people in this room because they are aware of the Road and Bridge Committee/April 21, 1998 Page 2 of 8