SUPPLEMENTAL INFORMATION - Laserfiche WebLink

Karen Gonzales rom: Pleasanton City Clerk ubject: A BAD DECISION--Lane Reduction on Owens Drive SUPPLEMENTAL MATERIAL From: Darlene Miller Provided to the City Council Sent:Saturday,January 13, 2018 8:52 AM After Distribution of Packet To: Mayor and City Council I , I b Subject:A BAD DECISION--Lane Reduction on Owens Drive Mto I am still dumbfounded as to why the City council allowed this reduction in lanes. As I see it, you sacrificed the good of the community for the good of one land developer. If you relied on a traffic model from the City's traffic engineer--obviously the model was wrong. I have a background in modelling from both my graduate education and corporate experience. Also, I was exposed to models that the City's traffic engineer creates through the East Pleasanton Specific Plan community meetings a few years ago. From those meetings, my understanding was that the City Engineer did NOT run sensitivity analyses on the input variables in his models (this is standard operating procedure) and something that the City Council should require. For example, in the EPSP model, the model had an input variable for"number of children per household." I believe this input was set to 1.5. Many residents complained about this. In my experience, values for input variables are only guesses. They may be highly thought through and researched guesses, but at the end of the day they are still just guesses (or some call them forecasts) and not facts. Since they are only guesses and not facts, it becomes imperative to run sensitivity analyses. So for example, the model should have been ran with the 1.5 guess being increased and decreased. hat is, scenarios should've been ran with the number of children per household set to 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5. When this is done, if the result of the model changes a lot by changing the value of an input variable, then one of the conclusions the Council could come to is that the model is what's called "highly sensitive"to the input variables. To put it more plainly,the model is NOT reliable. So you may have been making decisions based on unreliable data. At the EPSP, I stood up and spoke, and I told the group that in my experience of modeling, I could get models to say anything that I wanted them to--simply by changing the input variables. This is another reason why sensitivity analyses are so important--because it keeps everyone honest. I am completely in support of doing anything to change the current situation of one lane on Owens Drive. If going to two lanes in both directions is the only economically viable option now that this mistake has been made, then I support that. However I am incredibly disappointed that we got into this situation in the first place. I am asking the City Council to stop taking as gospel these models that the traffic engineer presents. Instead, I am asking the City Council to look at the inputs that the traffic engineer is using in the model, and for the more important input variables, to run sensitivity analyses before making any decisions in the future based on these models. Click here to report this email as spam. • i