The City’s Traffic expert has stated that 85 percent queuing is used in his design recommendations to save concrete. He has also stated that backups can/will occur at an intersection with 100 percent queuing.
Now there are valid reasons to use 85 percent queuing, but saving concrete is not a valid reason.
If, after the fact, an existing intersection that was designed without a left turn lane experiences chronic backups, and there is not enough room to add a left turn lane with sufficient queuing to alleviate the back up, then 85 percent queuing may be justified, although 85 percent queuing would likely not be sufficient to correct the backup problem.
No, really, an intersection with 15 percent more queuing capacity than the traffic expert’s current recommendations to the City will experience traffic backups. This is by design, and the intersection can have, and is even expected to experience, backups.
Current examples of 85 percent queuing designs are Ward and M St. (what a mess this intersection is, yet it is functioning as designed) and Sperry and Park Central Drive (Councilmember Novelli has already experienced a traffic backup at this intersection and the truck traffic is not yet at full capacity; this intersection is also functioning as designed).
Tuesday night the city council had the opportunity to require the pouring of more cement and change the 85 percent queuing left turn truck lanes from Sperry onto Haggerty. I stated that the queuing could be extended from 85 percent to between 200 percent and 300 percent queuing. If the single left turn lane from Sperry into the employee parking lot is eliminated and the double left turn lanes are extended from Haggerty through the proposed single left turn lane into the employee parking lot, the queuing could, if desired, actually be extended to approximately 362 percent. This is the time, the least expensive time, to fix/design/prevent future backups at the Haggerty and Sperry intersection.
The city now owns the backup problem that will exist on Sperry at Haggerty. Requiring a future developer south of Sperry, south of this project, to pay for the correction of a backup problem caused by the development north of Sperry just will NOT happen. The city will have to pay to correct this problem, and it will be expensive — many, many, times the cost of fixing it now.
I previously suggested eliminating the special access to and from I-5, not the right turn lane coming from Patterson. My suggestion would not have eliminated Fire Engine access into the parking lot.