Does Pasco’s Road 100 interchange need a $40M transformation? Here are some choices
Pasco officials want to hear from the public about options for changes at one of the busiest traffic corridors in the Tri-Cities.
The city of Pasco previously hosted a meeting to discuss alternatives for fixing traffic congestion at the Broadmoor Boulevard and Interstate 182 interchange, and now wants the public to weigh in on some choices.
The current issues are mostly related to eastbound traffic, with Broadmoor — which turns into Road 100 to the south — backing up in the afternoon as commuters are trying to get home to west Pasco.
The city wants to address those headaches and dangerous backups and also plan for huge growth expected in the area from a large-scale residential and retail project, including a proposed new Costco.
The changes would mostly be paid for by the city, and could cost as much as $40 million.
The first three proposals involve changes to the intersection that can be done individually or in combination.
The fourth, which engineers say will be the most effective to deal with the substantial future growth expected there, would involve a full overhaul of the intersection, creating what is known as a diverging diamond interchange.
A fifth option also is being considered, including improvements for pedestrians and bicyclists.
Getting ahead of growth
“We are looking at this as immediate future needs, we’re going to be looking out at the next 20 years, ” Public Works Director Steve Worley told the Herald. “So the goal of this project is to get ahead of the future development in the Broadmoor area.”
The area to the west of Broadmoor and Interstate 182, is set to see significant commercial and residential growth over the next few years.
More than 3,000 jobs are expected in the area from a large retail development and 7,000 new households from new subdivisions and apartments on the north side of the land, along Burns Road.
Several subdivisions already have been built north of Burns. Homes and apartments will be built on the south side of Burns, with retail between the housing and the Sandifur Parkway extension.
Long-term planning shows even more housing will fill in the far south and western areas of the development, extending all the way to the Columbia River.
Project Manager Aaron Berger with DKS Associates said many of the alternatives could be built at the same time or at different times, but don’t conflict with each other.
He said that alternatives for the north and south sections of the interchange could both be built, but they settled on the options presented because the most important factor is to find options that play well together.
Alternative 1
The first option involves changes to the interstate as it approaches Broadmoor.
It would entail adding dual eastbound off-ramp lanes, moving the exit past Broadmoor and into an off-ramp loop back to Broadmoor.
This option would minimize slowing down traffic on the interstate, while increasing off-ramp capacity.
Changes to the interstate would ultimately have to be approved by Washington state and the Federal Highway Administration.
That isn’t likely to create a setback though, because last year the state sent a letter to the Franklin County Planning Department outlining their concerns with the intersection, and Pasco has been working with them to find a solution.
Alternative 2
Alternative 2 is the option for improving the north end of the intersection.
This option would focus on the north side of the interchange, and add dual right turn lanes to the off-ramp on westbound Interstate 182, and a roundabout at Broadmoor and the current westbound entry/exit ramps just south of Harris Road.
Officials say this option would reduce delays at the intersection and improve pedestrian crossings.
It would also directly impact the future growth in the area, as Sandifur Parkway is set to be extended west across Broadmoor through the new retail and commercial area.
Alternative 3
This option is similar to Alternative 1, but focuses on the south portion of the interchange rather than the interstate.
It would see a new off-ramp loop exit to an updated signalized intersection or roundabout. Officials say it would simplify the intersection and improve pedestrian crossings.
One major area of concern is reducing the need for left turns when exiting the highway, with this option the majority of exiting traffic would make a right turn.
Alternatives 1 through 3 are designed to compliment each other if the city chooses to move forward with more than one. Should they choose to use all three, construction could be staggered to avoid a total closure of the intersection.
Alternative 4
Alternative 4 is a far more drastic change, but officials believe the holistic approach would alleviate current congestion issues, and account for future growth. Berger said it would be wise for the city to consider a long-term solution.
The concept they’ve presented is called a diverging diamond intersection, and would require the entire intersection to be closed during construction.
“From a feasibility perspective, considering the (challenges) right away and thinking ahead to what is the best solution long term, we settled on the DDI at this location,” Berger said.
Traffic flow would look like this: Commuters moving north on Broadmoor would find a signalized roundabout where eastbound 182 traffic currently exits.
This roundabout would slow traffic leading to the entrance and exit ramps for eastbound 182, and move through traffic into “cross points” at each end of the intersection.
These “cross points” then criss cross traffic on the bridge over the interstate, allowing the left-most lane to flow into the on-ramp for westbound 182 on the opposite side without needing to stop for a left turn signal.
Through traffic will then move into the roundabout on the south side and continue on. Traffic flow would look the same for southbound commuters.
Officials said there is little risk of oncoming traffic entering the wrong portion of the cross point, in areas where DDI’s are already in place, these opposing lanes are separated.
Bicycle and Pedestrian options
Some new bicycle and pedestrian options in the area could be built in addition the changes to the Broadmoor and 182 intersection.
One proposed option is a new trail on St. Thomas Drive, south of 182, that would lead to a bridge across the intersection aligned with Midland Lane.
If the city does not go with the diverging diamond, they could also narrow lanes on the current bridge to allow for a new sidewalk path, widen the current bridge or add new bridges on either side of the existing structure for bicycle and pedestrian traffic.
Public comments
Feedback from the last meeting about the intersection brought in 80 comments from the public. The majority of the comments centered on traffic congestion, pedestrian and bicycle issues and safety concerns.
Questions from the most recent meeting largely centered on questions about the effectiveness of roundabouts, and future planning.
“From a bicyclist or pedestrian standpoint a roundabout is about speed. Roundabouts are intended to slow vehicles down by the way the intersection is managed. Even the newer ones, you’ll notice the curve before you get there. That curve is intended to slow you down, so you can’t blast straight through at 45 mph,” Berger said.
“Pedestrians are also crossing fewer lanes of traffic. While you don’t have a signal, you have to cross five lanes or more in a traditional intersection, so the time you’re in the roadway is significantly longer,” he said.
Once feedback is taken into consideration, they hope to have state approval by late spring, and a workshop to give residents a final report in early summer. Their goal is to begin seeking bids on the project by year’s end.
“The idea here is that we want to have as much input as possible,” said DKS Communications Director Kendall Flint.
The city’s survey to collect feedback can be found at surveymonkey.com/r/pascoalts.
This story was originally published March 14, 2022 at 5:00 AM.
