In 2011, we will begin work to widen SR 9 between SR 524 (also called Maltby Road or 212th Street SE) north of Bothell and 176th St SE near Clearview. We will add one lane in each direction of the highway and we will add a raised median to separate oncoming traffic and limit access points for turning drivers.
Why is WSDOT widening this section of SR 9?
Over the last ten years, increased development and traffic have led to more congestion and more collisions on this section of the highway. There were 381 collisions in this segment of SR 9 in the last six years – an average of more than one collision per week. Of those collisions, 334 were rear-end collisions or collisions involving vehicles turning onto or off of SR 9. Both types of collisions are associated with increased congestion.
To improve safety and reduce congestion, we will double the number of through lanes on SR 9, provide additional turn lanes at 180th St SE, and consolidate driveways where possible. The additional capacity, improved intersections, and controlled access points will help reduce congestion and keep traffic moving. These improvements will also help reduce the high number of collisions involving turning drivers and the risk for serious crossover collisions.
What is the project timeline?
We are currently designing this project and will advertise it for competitive bidding in March 2011. We will begin construction in summer 2011 and expect to finish the project in 2013.
How will WSDOT improve safety in this section of SR 9?
How will WSDOT reduce collisions and congestion on this route?
Traffic volumes along this stretch of SR 9 have skyrocketed; more than 26,000 drivers now travel the route every day. Higher traffic volumes increase the risk of serious crossover and head-on collisions as drivers try to turn across heavy oncoming traffic.
To reduce serious collisions and keep traffic moving, we will add a raised median to separate oncoming traffic and limit access points for turning drivers. Raised medians work by eliminating left turns across oncoming traffic at access points on busy roads. Controlling where traffic can go minimizes the conflicts that lead to collisions.
The new design meets state regulations designed to keep drivers safe. The state legislature recognizes the need to manage access to improve safety, and requires us to install barrier on multi-lane highways of this type. Managing access with a raised median improves safety and reduces congestion by controlling access points so that turning and crossing movements occur at fewer locations.
How will drivers get to their homes and businesses?
To ensure access to businesses and homes, we will provide safe locations for U-turns. Drivers can make protected U-turns at designated U-turn locations, and then make a right turn into a business or residence. U-turns will be allowed at the following intersections:
- 212th St SE
- 197th St SE
- 188th St SE
- 180th St SE
- 176th St SE
How will the improvements affect businesses along SR 9?
Surveys of business owners along routes where raised medians have been installed show that most did not see a decline in their sales. In fact, many business owners believe that access management has actually improved their sales. One reason for this is that as traffic volumes increase, it becomes difficult and dangerous for drivers to enter and exit properties, particularly when they are closely-spaced. Businesses with safe and easy access are more inviting to customers.
Additionally, controlling access points with a raised median can also help reduce the congestion that results from frequent and closely-spaced driveways on busy roads. Traffic delays, including those caused by collisions, are bad for the economy and frustrating for business customers. If collisions and congestion become frequent, drivers will seek other routes. Access management helps keep traffic moving and can improve travel times, enhancing convenience for drivers.
Why not install a signal at 201st Street SE?
We studied traffic volumes at this intersection and determined that a signal is not needed at this time. While a signal could improve traffic flow for drivers on 201st St SE, it would likely cause significant delays and backups for northbound and southbound traffic on SR 9. In addition, in many cases traffic signals actually increase rear-end collisions due to drivers slowing or stopping unexpectedly.
To keep traffic moving on 201st St SE, we will add right- and left-turn pockets to create more capacity for drivers turning onto SR 9. View the proposed changes (pdf 386 kb)
What are your plans for 184th St SE and 188th St SE?
Like many of our projects, this project has been affected by the rising costs of construction and materials. To keep the project within budget, we looked at ways to reduce costs while still improving congestion and safety. One cost-saving measure we implemented was changing our plans for 188th St SE and 184th St SE (pdf 6.75 mb).
Initially, we planned to eliminate the connection from 188th St SE to SR 9 on the west side of the highway and build a new connection at 184th St SE. To reduce costs, we will not build a new connection at 184th St SE or eliminate access at 188th St SE. Instead, we will improve safety at 188th St SE by changing the roadway alignment to improve sight distance and by eliminating left turns onto SR 9. Many of the collisions at this intersection involve turning drivers.