The city staff have studied all of the concerns raised by the public and the council, and have summarized their final recommendation into a nine page issue paper which was released yesterday. You can read the issue paper by clicking Here

We asked the city staff to prepare this comprehensive issue paper at last week’s Transportation committee meeting on this topic. We felt like the complete set of factors and considerations about Duvall needed to be available to all of us (including council) prior to tomorrow’s city council meeting.

What was not clear prior to our Wednesday meeting, was that even if Duvall was “open”, it was going to have to experience numerous temporary closures because of fifty seperate utility trenches that have to be dug across the roadway. This is due in large part to the fact that all of the electric utilities are being undergrounded (yay!), but that makes trenching across the road necessary everywhere that wires used to cross it from above (to hook up homes and other buildings). Also, trenches are necessary for sewer and water connections…so drivers would have experienced delays, metal plates across the road, and lots of rocks and gravel everywhere.

Most significantly, the in-Renton widening of Duvall would take two years (500 work-days) with Duvall open, and one year (250 work-days) with it closed. This is important, because the Newcastle portion will be open in 18 months; when the Newcastle stretch of Duvall is complete, driving that portion will be SWEET (two lanes each way). But if Renton still has six months to go, Renton would be the center of a big mess.

In summary, the Council Transportation Committee (made up of Marcie Palmer, Don Persson, and me) have made numerous suggestions to mitigate the risks and impacts from closing Duvall; with these mitigations, we now feel that it is probably appropriate to close the road for the construction period.

Here are the primary mitigations:

To protect the school kids:

We will post a police officer at Sierra Heights during school arrival-departure hours, to ensure that posted spreed limits and other driver safety requirements are consistently observed.

We will not allow trucks on union during the school day (other than school buses).

We will re-stripe Union avenue, to add a third lane…a long dedicated left turn lane, into Sierra Heights parking lot, such that parents and bus drivers will not have to wait in the queue of drivers making their way to Bellevue on the peak AM hours.

We will add a temporary stop sign at the school if it becomes necessary.

We will encourage traffic to detour on 148th and May Valley Road in preference to Union Avenue, by way of signage, an preferences at the intersections of 95th, May Valley Road, and Duvall.

To make it manageable to drive to Bellevue:

We have reviewed detailed modeling of drive times, and found we can get people to Bellevue as quickly with these detours as we can by keeping Duvall open, through the use of preferences at the intersections of Duvall, May Valley Road, and SE 95th. This is because the choke-point on the trip to Bellevue will be the one lane that Newcastle has open, across the bridge (under construction) and through the construction zone. This one-lane will move slowly, so traffic in Renton will be backing up during peak hours whether or not we have Duvall open. With Duvall closed in most of Renton, we can mark a free-turn onto the open portion of Duvall (without a stop sign) at either 95th or at May Valley Road, whichever works best to get drivers onto Duvall. This is expected to work as well as keeping Duvall “open”, especially since it would be subject to closure during the 50 trenching operations mentioned above.

Other changes:

We will add an imporved left turn pocket (refuge pocket) for drivers truning left out of Summerwind onto highway 900 (Sunset). There is sufficient width, such that re-striping, and safety turtles will make it possible to get a long protected center lane to assist left-turning school-buses and automobiles.

So, in one year in Renton, and 18 months in Newcastle, Duvall will be open with two lanes, and traffic on 148th and Union will drop to lower levels than either road has experienced in years. The new, wider Duvall will accommodate over twice as much volume as before, and make the commuter short-cuts on Union and 148th largely ineffective and unnecessary.

Because of all of the above issues, the $ 3,000,000 savings is not even the biggest factor. It’s possible we would chose to close Duvall in any case, just to realize the time savings.

As always, I value YOUR opinion on all this! So please feel free to share your comments!