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MINUTES PLANNING COMMISSION Page 11 John Foresthal, traffic engineer, Oakland spoke, stating he was requested to review the Pang report and evaluate the conclusions. He felt the trip generation rate was a little high. He doesn't believe a 50% cross traffic figure should be used for this particular lenk. He said there are driveways, cross streets and control by stop signs. He felt 25% applies. Byron Larson, George Nolte and Associates, has been a traffic engineer for 17 years and seven of this was working for a municipality. He read his report. He felt that because of the size of the homes, it is reasonable to assume they will be occupied by small families and may have some elderly couples. He referred to the Caltrans Survey report of a 21 conventional subdivisions. Seven trips per day is an appropriate figure. This is 38% less than Pang Chairman Jamieson asked about the five trip per day standard used by Caltrans survey with a typical 21 unit subdivision and asked why Mr. Larson based his report upon seven trips per day. Mr. Larson indicated that the residential trip generation factors varies with the types of residential units provided. He read the Caltrans list. Chairman Jamieson had a problem with 9.5 in the Pang estimate and 7 in Mr. Larsons. Mike Valley said they tried to balance off the figures between an average townhouse in town at the present time and tried to balance off at seven. Mr. Larson felt that with the type of tenants they will be getting a realistic figure is 7• Commissioner .Wilson had problems with words like "assume" and "approxiamtely" and if four different consultants are hired there are four different opinions. He said a previous speaker said he couldn't get through the signal so there must be a problem in the area. Chairman Jamieson reiterated what Mr. Pang said that traffic isn't an exact science. Mr. Damon, Barton Ashman, presented his report. With regard to trip generation rate he looked at density and referred to the Caltrans Survey. He strongly recommended 33% trip generation reduction relative to the development. He believes this to be based on realistic information. He felt it to also be erroneous to use a 50%/50% split. He said he assumed a theoretical link capacity of 900 vehicles. ' Chairman Jamieson gave Mr. Pang an opportunity to rebut arguments made by the other traffic consultants. Chairman Jamieson indicated that Mr. Pang's study was based on 237 units and in fact the number of units have been reduced to 200. Mr. Pang indicated that they checked the intersection of First and Vineyard using four/five phase signals. They found this wouldn't work so they went to a three phase signal. There are 72 driveways and a bikeway proposed and there is no parking on one side of Vineyard Avenue. He said a 50% green time was an assumption. He said one could increase the speed but he wouldn't recommend that. He said there is a 21% differential to Bernal. Mr. Griffin asked Mr. Pang at LOS E how many signal lights should a person have to sit through. Mr. Pang said normally this would be three or more. Mr. Martin indicated that the units have been reduced from 237 to 200 and this is an 18.5 reduction which is not taken into account.