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HomeMy WebLinkAboutHUMAN BEAN AT SPRING CREEK - Filed GC-GENERAL CORRESPONDENCE -M E M O R A N D U M Date: February 15, 2007 To: Troy Jones Shelby Sommer From: Martina Wilkinson, P.E. PTOE RE: Human Bean Questions posed by Planning and Zoning board members are shown m bold. City traffic staff responses are in italics, and additional information is shown below that. 1. Why doesn't the T.I.S. address stacking at the College access? Does City staff anticipate any issues with stacking at the proposed access? At the time of the scoping for the TIS, it was not believed that stacking on South College would be a problem when considering the "double drive thru" and the set back from the roadway. The initial trip generation estimate actually put the level of TIS at Memorandum " but we decided to also look at the background traffic for the short term horizon. If a stacking analysis is requested by the P&Z Board; then it would be prudent to pull the item from the agenda and allow the applicants traffic engineer to prepare the analysis for next month's meeting". It is important that the vehicles entering in the development (especially in the am peak hour) waiting for service do not stack into the roadway. The current design shows that there is stacking room on the property for at least 10 vehicles. Assuming 31 entering cars in the peak hour, and a very conservative 5 minute wait, that would be a total of 155 vehicle waiting minutes, or an average of less than two cars present at the ordering windows during the am peak. It is recognized the am traffic.does notarrive entirely consistently, but with a safety margin of 5 fold, this appears adequate. The, North College Human Bean did on occasion stack onto the roadway during the am peak, prior to the reconstruction that allowed the double drive thru lane. Since the reconstruction which, like the proposed South College Human Bean, has significantly more storage available, the stacking doesn't appear to be an issue on College Avenue. 2. The trip generation data provided in the T.I.S. includes weekends (avg taken for 31 days) which, in the opinion of one PU Board member, would be relatively low volume days compared to weekdays. Therefore, true representative trip 5 1, y generation averages may be skewed and should be higher. Basically, the Board member would like to see the 31 day average calculated without the weekends included. Given any change in the average trip generation calculation (higher ADT), how will this change the design requirements of this project? Will a higher ADT warrant the need for a right turn lane to the site or an accel/decel lane? There are not many samples from which to draw estimates for a dive-thru coffee shop. The applicant's engineer used ITE information and a variety of other sources and all are consistent. / do not believe that recalculating the trip generation is going to make much, if any difference in the analysis. As for the right tum lane, there are three overriding issues that would prevent the construction of right turn lane. First, LUCASS, Table 8-4 does not require a right turn lane on 6 lane arterials until the right turn volume exceeds 200 vehicles. Second, the State Highway Access Code does not require right turn deceleration on a 40 mph facility until the volume exceeds 50 vehicles. Finally, there is approximately 50 feet between the driveway and Spring Creek that would prevent the construction of a right turn lane". As Eric noted; the TIS drew from a number of sources for trip generation data. Both the ITE information as well as the Oregon data were for weekdays only, and is consistent with the assumed trip generation.for this study. In addition, by reviewing the auxiliary lane warrants, the trip generation could. be significantly higher (60% higher) before the warrant for an auxiliary lane is met. 3. Finally, the U.S. does not include any background traffic analysis for the access to the Human Bean site. This property was owned, divided and sold by the Eye. Care Center next door so it seems reasonable that this existing access point was and will continue to be used by the Eye Center customers since they will be able to access the Eye Center parking lot from the Human Bean access. Additionally, the Eye Center customers may also use the Human Bean parking spaces unless certain parking restriction signage and enforcement is implemented. Basically, it is the Board members opinion that the eye center trip generation (or a. reasonable portion of it) should be included in the analysis of the Human Bean access and trip generation average calculations. The Board member is correct that the analysis did not include the background traffic from the Eye Center. The Eye Center does not open until 9:O0am which is outside the AM peak hour and the PM peak hour trip generation of the coffee shop is so low that it appears to be insignificant". Again, as noted. above, there is quite a bit of capacity in the turning volumes before turn lane warrants are met. In fact, there is enough capacity that the entire Vision Eyeland center's ITE trip generation (which does assume some am peak hour trips) could be added and the CDOT warrant for a lane would still not be met.