Monday, July 26, 2021

New ramp meter alleviates traffic congestion, improves safety at SR 167 to northbound I-405

By Jordan Longacre

A recently installed ramp meter on State Route 167 where drivers merge onto northbound Interstate 405 in Renton will go live for the first time on Tuesday, July 27. Anyone who has merged onto northbound I-405 from SR 167 has likely been caught in heavy traffic or even experienced a collision at this location. The SR 167 ramp meter will help alleviate congestion and incidents and prevent free-flowing vehicles from hitting a dead-stop at the I-405 merge point, improving efficiency and safety for drivers.

The new ramp meter will regulate traffic during the peak morning commute from 6 a.m. to noon and intermittently during the afternoon in response to heavier traffic. This traffic change is part of an adaptive freeway metering system that automatically activates and adjusts each ramp meter based on current conditions. Additionally, our traffic engineers will monitor the meter timing and adjust as needed to ensure the best traffic flow.

Why do we meter?
Without ramp meters, vehicles entering the freeway merge together in tightly packed groups, which can cause drivers on the highway to slow down or even stop as they merge. This results in slower speeds, both on the freeway and on the ramp, quickly contributing stop-and-go conditions. By pacing the vehicles evenly at a controlled rate, the merge is much smoother.

In the case of SR 167 to I-405, vehicles currently go from traveling at 60 mph to a dead-stop near the merge point as they enter I-405. The meter prevents tightly spaced groups of cars from merging onto the freeway at once, which will keep I-405 flowing smoother during those times. The largest benefit of the new ramp meter will be at the beginning and the end of the peak commute times. By metering at the beginning of the commute, free flow on I-405 continues longer. Metering at the end of the commute ensures free flow returns faster, improving travel for all motorists.

How will a ramp meter be effective and efficient here?
Based on recent data collected along SR 167 and I-405, traffic along SR 167 is now exceeding 2017-2019 pre-pandemic averages and volumes along I-405 are within 10 percent of 2017-2019 pre-pandemic averages. With traffic on I-405 likely to continue increasing, the ramp meter will allow us to better manage the high traffic volumes entering I-405. If the meter can manage SR 167 now, as our analysis shows, it can manage pre-COVID volumes due to the similarity to the 2017-2019 midweek average.
  • Ramp meters automatically respond to changing traffic conditions. If traffic is flowing well, then the meter is not activated. During periods when traffic flow is beginning to slow down or conditions have become congested, ramp meters are in operation and automatically adjust to move vehicles more efficiently.
  • Ramp meters really show their effectiveness when it comes to managing traffic following a crash on the freeway, helping traffic recover quicker.
  • The ramp meter can help delay and/or prevent congestion from extending past the SR 167/I-405 merge point.
  • The SR 167 ramp meter can help alleviate and prevent free-flowing vehicles from hitting a dead-stop at the I-405 merge point.
  • A portion of the ramp shoulder area will serve as an additional lane during metering periods, preventing ramp metering backups onto SR 167.
  • Ramp meters are designed to help evenly pace vehicles merging onto the freeway, providing consistent gaps between vehicles, rather than multiple vehicles flooding onto the highway at once.
  • Ramp meters create a steadier flow of traffic onto the highway and reduce travel times.
A look at the direct connector HOV ramp that connects SR 167 to northbound I-405 in Renton.

How does this improve safety?
Ramp meters are an effective tool used to operate state highways safely. More than half of the collisions over the past five years have occurred where SR 167 merges onto northbound I-405.
  • Ramp meters improve safety by allowing one vehicle at a time to merge onto the interstate, reducing the severity and number of collisions due to merging traffic.
  • Gaps between merging vehicles will make the merge easier for drivers and reduce the risk of collisions.
What should I expect as a driver?
For drivers who normally use the SR 167 to I-405 ramp, one notable change will be the addition of a 1,250-foot shoulder lane that will also be metered. The ramp meter will have two signals that will alternate green lights to cycle vehicles through at an even pace. Signs are in place indicating both lanes are available when the ramp is metered.
  • Our traffic studies have shown drivers currently spend about 3 to 8 minutes on the SR 167 ramp to I-405. With the operation of the ramp meter, we expect morning commuters to experience similar delays on the ramp, while some evening commuters may experience a slight increase in ramp delays, but with the added benefit of safely merging into traffic flow on northbound I-405.
  • More consistent delays on the ramp for drivers will help provide better merging conditions, reducing overall congestion in the area.
The shoulder of the SR 167/I-405 ramp will be converted to a 1,250-foot storage lane (here on the far right) to be used for peak travel times to help keep traffic moving.

Will HOV and transit be able to use the ramp meter?
Carpools, vanpools and transit traffic will be able to use the I-405 Direct Connector HOV flyover ramp that connects SR 167 to I-405 via the leftmost travel lane but can also use the metered general-purpose ramp if they choose.
  • Metering the exit to I-405 would likely encourage eligible motorists to use the Direct Connector HOV flyover ramp.
  • The Direct Connector HOV flyover ramp adds additional capacity (HOV, transit, emergency vehicles) and reduces traffic volume that would have been using the normal ramp in previous conditions, again alleviating traffic congestion.
  • The general purpose and HOV lanes on northbound SR 167 just north of the South 180th Street interchange are excluded from the toll algorithm as the High Occupancy Toll Lane ends in this location.
  • We will be monitoring traffic on the Direct Connector before and after metering begins and will make recommendations regarding enforcement.

Tuesday, July 20, 2021

Multiple wildfires likely to keep stretch of SR 20 closed through at least July

By Mike Allende

As you may be aware, the Varden, Delancy and Cedar Creek fires have been burning in Okanogan County for most of July. This has led to the closure of a stretch of the SR 20 North Cascades Highway, currently now stretching from mileposts 165 to 185, west of Mazama in the Methow Valley. Emergency responders requested the closure for safety and to allow them to stage equipment to battle the fires. The closure also is helping evacuations in the area.

Despite the incredible efforts of the firefighters, the fires continue to expand and emergency personnel now advise us that the highway closure will likely be in place at least through July and potentially longer.

We know road closures are frustrating and we don’t close them unless it’s necessary for safety. In this case, the requests of those tackling these dangerous conditions along with the related evacuations – including Okanogan Fire District and the National Forest Service – make clear that this closure is needed for the safety of everyone.

Three large wildfires burning in Okanogan County forced the closure of a stretch of the SR 20 North Cascades Highway west of Mazama.

We also recognize that the North Cascades Highway is a popular destination this time of year for travel between the beautiful Skagit and Methow valleys. The good news is, some of the most popular sites are still accessible, it just may take a little longer to get there.

OK, how do I get there?

This time of year, many people travel from the west side to Winthrop, Twisp Mazama and other areas that are easily reached once the SR 20 North Cascades Highway reopens from its winter closure in the spring. And while that highway does provide a convenient link between west and east, it’s not the only way to reach the Methow.

Typically, it takes about three hours or so to go from Seattle to Winthrop using SR 20. Getting there with that highway closed will add about 1½ hours to your trip. The most common way is:

·         I-90 eastbound for about 82 miles to exit 85

·         Take US 970 northbound toward Wenatchee

·         Continue on US 970/SR 10 for about 10 miles. This turns into US 97, which you’ll stay on for about 35 miles northbound

·         Merge onto eastbound US 2/northbound US 97 and US 97 north will take you into Twisp/Winthrop.

Alternatively, you could take US 2 over Stevens Pass through Leavenworth:

·         Take I-5 northbound to Exit 194/eastbound US 2 in Everett

·         Continue on US 2 for 107 miles, over Stevens Pass and through Leavenworth to Wenatchee

·         Take the US 2/US 97 north ramp to junction of US 2/97 and SR 28 in East Wenatchee and go left onto US 2/US 97 toward Orondo/Okanogan

·         Continue 57 miles toward junction of US 97/SR 153 south of Pateros and take a left onto SR 153 west to Winthrop. Continue for 40 miles to Winthrop.

Be sure to consult your favorite mapping app as it will help guide you where you need to go.

What’s open on SR 20?

The most popular destinations on SR 20 tend to be Diablo Lake and the Washington Pass overlook. They are truly beautiful locations with amazing views. The good news is that both are still open and accessible as they are west of the closure. You just won’t be able to go much further east than Washington Pass, including down into the Methow Valley. Also note that the North Cascades Highway is extremely popular and like most of the most popular recreation destinations in our state, it can get very crowded. Be sure to have backup plans if your preferred spot is full and never park illegally on the sides of the highway.

Remember that services are limited as you head into the mountains.  Gas stations, public rest areas, cell service and turn around points become increasingly limited heading east into Rainy Pass and Washington Pass.  Running out of gas or otherwise becoming stranded will make for a much longer, more stressful trip.

A look at where the road closure is compared to Washington Pass and Diablo Lake. Note that the unpredictability of fire means the closure points can move with little notice.

But is it safe?

If a highway isn’t safe, we would close it until it was. That said, there are fires burning east of Washington Pass and fires can be unpredictable. They can also lead to fast-changing conditions, road closures and delays. We encourage anyone traveling to areas where there is active fire activity to check with local emergency responders to see what the threat level is and also encourage people to research what the air condition is before they head to their destination.

You can also download our app for road updates, call the 511 travel information number and check our travel alerts page for more information.

Be prepared

Wherever you’re heading this time of year – but especially if you’re headed to areas with active fires – be sure you and your vehicle are prepared. As we mentioned, fires are unpredictable so road closures and delays can happen with little warning. Be sure you have plenty of gas, water, food, cell phone charger and other items you might need in an emergency. And be sure your vehicle is well maintained.

Those who are traveling in the area of active fires should be prepared for potential road closures or delays as they can happen quickly.

Closed means closed

It still amazes us that this happens, but we continue to get reports from those staffing the road closures that people are attempting to go around the closures. So to be clear:

·         There are no nearby alternate routes around the closure. There are no Forest Service roads or other side roads open that allow access. It’s closed. Closed.  You can’t go through. Closed.

·         Trying to get through a closed road puts you and others in the area at risk. There are literally fires burning nearby. You should be avoiding that, not driving into it.

·         If you go through a closure and get stuck, emergency responders including firefighters have to go save you. That puts them at even more risk and also takes them away from what they should be doing, which is fighting the fires that led to the closure.

We understand that there’s never a good time to close a road, especially a very popular summertime route like SR 20. We would love to have this route open, but safety of those responding to the fires and for the public is always No. 1. So until we get the all clear from the emergency responders battling to keep us all safe, the road must remain closed and we appreciate your understanding and cooperation.

With most paving complete, Revive I-5 shifts to expansion joints

UPDATE Thursday, July 22: The next scheduled Revive I-5 weekend closure - July 30 to Aug. 2 - has been canceled. Be sure to check the project website linked below for updates on the schedule.

By Tom Pearce

This past weekend our contractor finished most grinding and paving portions of our Revive I-5 project on the southbound freeway between I-90 and Spokane Street in Seattle. Crews began by grinding I-5 to smooth the surface during overnight shifts. During two weekends when lanes were reduced, they repaved a thin layer of polyester concrete, which is more durable than regular concrete.

We have repaved about 1¼ miles of all lanes of this section of southbound I-5, which has anywhere from three to five lanes. With the paving mostly finished, now we’ll turn our attention to expansion joints in the same section of freeway. 

No easy task replacing 56 expansion joints

This part of the freeway is built on piers like a bridge, so it has 40 expansion joints that allow it to expand and contract with weather changes. If you drive this section very often, you know the joints need to be replaced. In addition to the occasional bump or metallic clunking sound you may encounter, we’ve had several break in the past few months, requiring emergency repairs on weekday mornings or afternoons. That creates unplanned backups and delays.

When an expansion joint breaks, we have to repair it right away regardless of traffic and time of day.

In addition to those on the main section of the highway, we have 16 other expansion joints to replace on ramps that serve this part of the freeway. Replacing just half of a joint takes an entire weekend. We’ll do several halves during each closure, but it’s going to take at least 14 more weekends between now and summer 2022 to replace all of them.

Why so long?

Yes, that makes for a long project, but there are several factors. First is events in Seattle. When a weekend sporting event or concert brings an additional 35,000 to 65,000 people to the area, it’s very difficult to schedule work.

Then there’s the material – when we replace these expansion joints, we’ll use the more durable polyester concrete. But that limits working conditions – it needs to be more than 50 degrees Fahrenheit and completely dry to pave this type of concrete.

Polyester concrete is more durable but it requires dry weather and moderate temperatures.

We also need to plan ahead for this work to be sure we can get the materials we need and let you know we’re going to work. The weather, materials and notification time pretty much eliminate working during the winter as well as much of the spring and fall.

Stay looped in to the project schedule by checking the website. You can find info about the next weekend closure – July 30 to Aug. 2 – on the project page.

I’m always looking for a silver lining. For this project, while we’ll be working a lot of weekends, we’re going to wrap up most of the weeknight work by early August. A lot of people think the freeway is empty at night. I can guarantee you it is not – when night work creates backups, I hear from people who drive then. Besides, it’s not practical to replace expansion joints during overnight shifts – it would take much longer and final product would not be as strong.

We know that weekend lane reductions are hard on a lot of people. At least this way, you can plan around the work, unlike when a joint suddenly breaks and we need to do an emergency repair. Thanks for your patience!

Wednesday, July 14, 2021

Buckle up: Construction starts this summer on the SR 520/I-5 Express Lanes Connection Project

By Amanda Christopher

Despite all the negative effects of the COVID-19 pandemic, our largest county, King, still added 34,000 new residents in 2020. By 2050, the central Puget Sound region is predicted to add 1.8 million more people and another 1.2 million jobs, according to the Puget Sound Regional Council's VISION 2050 report.

The region's population and employment boom has been especially pronounced in Seattle's South Lake Union neighborhood. At the same time, the Eastside's technology-driven cities continue to grow steadily. This ongoing growth underscores the importance of a safe, reliable transit/HOV link between Seattle and the Eastside via State Route 520.

To that end, we're beginning construction of a new project this summer in Seattle – the SR 520/I-5 Express Lanes Connection Project. This project will connect SR 520's new transit/HOV system to the I-5 express lanes, creating a direct bus and carpool connection between the Eastside, South Lake Union and downtown Seattle.

The work is part of our overall "Rest of the West" program – a series of safety and mobility enhancements along the SR 520 corridor in Seattle. Construction on the SR 520/I-5 Connection project is slated to begin soon and take about three years to complete. The Legislature's 2015 Connecting Washington transportation legislation provides the project's funding.

This project will deliver several key benefits to improve travel speed and reliability:
  1. A new ramp between SR 520 and the I-5 express lanes for buses and carpools.
  2. A new, reversible transit/HOV lane along the I-5 express lanes, running between I-5's interchanges with SR 520 and Mercer Street. (Traffic moves southbound in these lanes during the weekday morning commute, and northbound during the afternoon/evening commute.)
  3. A reconfigured Mercer Street on-/off-ramp to and from the I-5 express lanes for buses and carpools.
A look at the key features of the I-5/SR 520 connections project

Building for the future

Although the COVID-19 pandemic caused a significant decrease in traffic volumes and transit ridership throughout the state – including on SR 520 and I-5 – we're building for the future. The improvements from this project will serve the region for at least the next 75 years as our population and economy continue to grow. Already we're beginning to see traffic and transit volumes rebound as businesses reopen and workers begin returning to the office.

Overall, the $4.5 billion SR 520 Program is reconstructing the highway from I-405 in Bellevue to I-5 in Seattle. When our remaining SR 520 improvements in Seattle are complete, we expect about a 30-minute reduction in peak-period travel time for buses and carpools between the Eastside and South Lake Union. We also expect to see an increase in additional daily transit trips/riders. We're working closely with our transit agency partners at Sound Transit and King County Metro, as well as the city of Seattle, to confirm future bus service and routes on the highway and into South Lake Union.

A couple other important notes:
  • The new direct-access ramp and reversible express lane initially will open to buses only; carpools won't be able to use the new ramp until the completion of the Portage Bay Bridge and Roanoke Lid Project. This phased approach will help provide safer merges for buses while the Portage Bay Bridge replacement is under construction.
  • While the SR 520/I-5 connection will improve travel for buses and carpools, this project does not address the "Mercer Weave" for motorists crossing several general-purpose lanes of traffic when merging from SR 520 onto southbound I-5 and then exiting at Mercer Street.
    • Untangling the "Mercer Weave" would require a separate, legislatively directed I-5 project in the future that is not currently planned or funded.
An aerial view of the SR 520/I-5 interchange looking southwest toward Lake Union and downtown Seattle. The future SR 520/I-5 express lanes ramp's location is in orange

What to expect during construction
As with any major construction project, while we're excited for the end result, we know the work will present some challenges and trade-offs for the community. Nearby neighbors may experience increased noise, truck traffic and nighttime lighting. And travelers may see delays, detours and temporary road closures as crews work to safely and quickly build this new connection.

Because this project is taking place right in the middle of two major highways – I-5 and SR 520 – much of the work must occur at night. This is for a few key reasons:
  • Working at night with less traffic will provide a safer work environment both for the contractor and for the traveling public.
  • Night work will avoid disruptions to daytime traffic on SR 520 and I-5, two vital routes for weekday commuters.
  • Working at night allows us to shorten the overall project duration, which reduces the length of time we're affecting the surrounding communities and reduces construction costs to taxpayers.
We recognize that working at night can be especially disruptive for neighborhoods closest to the work zone. As part of this project, we were granted a project-long nighttime noise variance from the city of Seattle. The variance lays out specific measures our contractor must and will take to mitigate effects on nearby residents, including advanced notice of noisy work, limiting impact work (such as jackhammering and pile driving) at night, and other adjustments such as not using compression brakes or letting equipment idle. You can read more about the variance by visiting the Seattle Services Portal, project number 6733975-NV.

In addition to this noise variance, we developed a Community Construction Management Plan that details the actions our contractor crews will follow to limit the effects of construction on nearby neighbors and travelers. This is a living document that can be updated periodically based on community feedback.
The SR 520/I-5 project will add a new connection between two of the Puget Sound area's busiest highways.

In addition to noise and other effects such as dust and added lighting, we know that a major project like this will bring delays and highway closures for drivers in the area. This may include temporary off-ramp detours, closing the I-5 express lanes earlier in the evening, and opening the express lanes later in the morning. As with any major traffic effect, we'll be sure to communicate these closures in advance so drivers can make alternate plans.

Staying informed
There are a number of ways to stay informed during SR 520 construction:
  • Call our 24-hour construction hotline (206-316-2559) with pressing questions or concerns.
  • Email SR 520 staff with your questions about the project or construction activities.
  • Visit the SR 520 Construction Corner for the most up-to-date information on closures and construction effects.
  • Visit the SR 520/I-5 Express Lanes Connection Project website to find general project information.
  • Follow us on Twitter @wsdot_520 to get key news and updates about the SR 520 program.
  • Get weekly updates via email by visiting our email updates page, enter your email address, and under "Construction Reports" select "SR 520 Rest of the West News"