We get plenty of questions about SR 18 over Tiger Mountain, especially following collisions. Unfortunately, there are no simple – or low-cost – solutions to improving the highway.
At first glance, installing a center barrier seems like a straightforward and inexpensive solution. But there’s actually much more to it.
A center barrier requires six feet – at a minimum – down the center of the highway. You need room for the barrier and a few feet of space between the barrier and vehicles. To make that happen, we would need to move traffic to the outside shoulders. OK, so, just do that, right?
Well, again, it’s not that easy.
In many areas, SR 18 would need to be widened to accommodate the barrier, moving traffic to the existing shoulder and rebuilding the shoulder to become a lane. The shoulder as it is now isn’t paved to what is known as “full depth,” meaning it’s not built to handle the weight of traffic thousands of vehicles that would use it each day would present. We would need to excavate the existing shoulders to create a new roadway before traffic could drive on it. Even with this portion, several feet would be needed for a new shoulder for stalled or disabled vehicles to safely pull off the travel lanes.
|Sections of SR 18 would need to be widened in order to place a center barrier in the roadway.|
There are also several fish barriers – culverts or bridges that don’t allow fish to easily pass through the area -- along that stretch which would need to be replaced during a widening project, and several unstable slopes would need to be addressed. There also is no funding to widen SR 18 between Issaquah-Hobart Road and Deep Creek at this point. The Legislature has provided us $1 million to complete an initial assessment of how much it would cost to design and build a wider SR 18, and those funds become available in the next year. Once that work is done funding would be needed for the design work and construction.
|While some funding has been provided to assess the cost of widening SR 18,|
no funding has been provided for design or construction.
There are no simple solutions to highway safety. We all play a role in making sure everyone stays safe on the highways. We’ll continue to work within the resources we have to enhance roadway safety and we hope motorists drive safely on the roads. As funding becomes available we’ll look for more ways to improve the highway system for all users.