Traffic signals or roundabouts?
That’s the big question officials with the city of Sumner will be asking the public at the upcoming “State Route 410 Bottleneck Open House” scheduled for 4 to 7 p.m. Nov. 9 at Sumner City Hall, 1104 Maple St.
The event will be open to the public and provide information about updates to the bottleneck and details on design options to relieve backup along Traffic Avenue and East Main.
“People will be able to give us some feedback about design,” said Carmen Palmer, the city’s communications director. “The remaining question is about roundabouts or traffic signals — there are pros and cons for both of them.”
The city was looking at six options for construction on the bottleneck, but some were ruled out due to high cost or problematic routes for non-motorized facilities, such as trails.
Now, the plans are narrowed down to two options, both of which will reuse the existing bridge while adding another lane.
“The bridge looks to be in good shape — it’s just too small for the amount of traffic,” said Jason Van Gilder, associate city engineer.
The difference lies mainly in design of the intersections.
People will be able to give us some feedback about design. The remaining question is about roundabouts or traffic signals — there are pros and cons for both of them.
Carmen Palmer, Sumner communications director
“Roundabouts are a good solution in a lot of situations,” said Van Gilder, adding that they’re less expensive to build and cause fewer accidents.
But there’s the other side to consider, too. Roundabouts are more difficult to navigate for industrial truckers — who make up a significant portion of those who utilize that route — and might only relieve part of the backup.
“Roundabouts tend to work better when you have lower volume of traffic coming from all sides,” said Van Gilder. “(At the bottleneck) we tend to have backup in certain directions.”
In the morning, it’s not unusual for drivers to find backup on East Main all the way to Shaw Road. In the evenings, a heavy concentration of traffic coming out of Sumner’s industrial center combined with people getting off work at the transit center hits Traffic Avenue hard.
Traffic lights are another option for fixing the problem, but comes with its advantages and disadvantages, too.
Signals might relieve the bottleneck more effectively for peak traffic periods, but are more expensive and pose a risk for non-motorized travelers crossing the intersection.
“Getting across the existing bridge is a bit precarious,” Van Gilder said. “Installing a wider sidewalk is something that could accommodate pedestrians and bicyclists.”
Of the project’s $18 million cost, the city has $8 million secured so far. The state of Washington, Port of Tacoma, Freight Mobility Strategic Investment Board, private funding and the city of Sumner have all contributed to the funding so far.
Sound Transit also helped in the funding in conjunction with its future plan to expand its train station in Sumner.
“The city would like to see this (project) happen before that does,” Van Gilder said, adding that the expansion of the transit center would mean more activity across Traffic Avenue.
The planning study, design and funding for construction of the bottleneck are still underway, but the city has plans for construction in 2019.
For now, city officials are asking for the public to weigh in at the open house on Nov. 9.