Peak-Use shoulder lanes

WSDOT is opening peak-use shoulder lanes in strategic areas throughout the state. This construction approach allows us to add more space for travelers in a quicker and more cost-effective way than expanding highways.

Visualization of peak-use shoulder lanesWhat is a peak-use shoulder lane?

As the name implies, drivers may use the designated shoulder in specific areas as an additional lane during times with heavy congestion.

How do I use a peak-use shoulder lane?

In general, all vehicles can use peak-use shoulder lanes as another regular lane when they are open to traffic. There are no particular occupancy requirements, and the speed limit is the same as the rest of the roadway. Vehicles over 10,000 GVW are prohibited from using  peak-use shoulder lanes, with the exception of buses.

When are these lanes open to traffic?

Check the signage in the area to know when you can use the peak-use shoulder lanes. WSDOT currently uses two types of lanes:

  • Static, which are open to traffic during set hours specified on the signage.
  • Dynamic, which are open to traffic when electronic lane control signs indicate that the lane is open with a green arrow.

Why can't we have peak-use shoulder lanes everywhere?

There are plenty of engineering considerations for deciding where peak-use shoulder lanes are appropriate. Shoulders must have the width and pavement thickness to accommodate traffic safely. We also need to consider whether there's enough capacity to handle this new lane of traffic farther down the highway.  

What happens if there's an incident in the shoulder?

In the event of an emergency or blocking vehicle during lane operations, the peak-use shoulder will be closed (in the case of the dynamic lanes, using the overhead lane control signs) until the problem is able to be cleared.

Where can I use peak-use shoulder lanes today?

Interstate 405
The I-405 peak-use shoulder lane runs on northbound I-405 between SR 527 and I-5. This lane is dynamically controlled with overhead electronic signs that show when the lane is open and closed to traffic. The lane is generally open during the afternoon weekday commute.

US 2
The US 2 peak-use shoulder lane runs along the eastbound trestle between Everett and Lake Stevens/Snohomish. Statically operated, it is open 2 p.m. to 7 p.m. Monday to Friday.

Where will WSDOT open peak-use shoulder lanes in the future?

  • State Route 14 - A peak-use shoulder lane will extend along westbound SR 14 for one and a half miles, between Southeast 164th Avenue and I-205 in Vancouver. When traffic is heavy, travelers on westbound SR 14 who are exiting to northbound I-205 will need to travel on the right shoulder, creating an additional lane of travel. This project goes to design in 2017 and construction is scheduled to begin in 2020.