Improving US 2 and Rice Road in Sultan
How will the improvements be funded?
In 2008, Governor Gregoire and the legislature invested $10 million to enhance safety on US 2 between Monroe and Gold Bar. We started work on the first four improvements in June 2010 and will begin work at Fern Bluff Road west of Sultan in summer 2011. Due to the current economic climate, the contractor’s bid to construct the first four improvements was lower than our engineering estimate. The remaining funds will be used to design and build long-term improvements at US 2 and Rice Road.
We know that improving safety at US 2 and Rice Road is a top priority for the community and the city of Sultan. The remaining funding will allow us to make a substantial improvement to reduce the risk of serious collisions at this intersection.
Why isn’t WSDOT installing a traffic signal, even temporarily?
Traffic engineers follow specific, uniform guidelines to determine whether a traffic signal is necessary and will be an effective traffic control tool. These nationally-adopted guidelines include criteria such as traffic volumes, pedestrian volumes, school crossings, collision history and other factors. The US 2 and Rice Road intersection does not meet the guidelines for a traffic signal. A traffic signal could increase the risk of collisions at this intersection.
Studies have repeatedly shown that roundabouts are safer than traditional intersections – those controlled with stop signs or a signal. In fact, roundabouts have been shown to substantially reduce injury and fatal collisions. In the right application, a traffic signal can increase safety. However, at this location, a traffic signal would likely lead to an increase in rear-end collisions, and would not eliminate potential conflict points for turning drivers. Collisions at signalized intersections are typically more severe than those at roundabouts because they tend to occur at higher rates of speed and at higher impact angles.
A traffic signal would also increase delays, because US 2 drivers would have to stop for Rice Road/339th Avenue SE traffic. Minor side street traffic could experience excessive delay, particularly during off-peak hours. Roundabouts, on the other hand, promote a continuous flow of traffic; drivers go through the intersection at a slow speed, rather than coming to a complete stop for a signal.
Why isn’t WSDOT lowering the speed limit on US 2, even temporarily?
Lowering the speed limit at US 2 and Rice Road would not be a safe or effective change. Speed limits are based on the 85th percentile speed – that is, the speed that 85 out of 100 vehicles travel at or below. We know from our own experience and from national studies that people will not automatically drive slower when the speed limit is lowered. In fact, our data shows that roadways with speed limits set at the 85th percentile speed have fewer collisions.
Our recent speed study shows that the 85th percentile speed between Sultan-Basin Road and Sultan-Startup Road is 50 mph, which is the posted speed limit. The 85th percentile speed is based on the principle that reasonable drivers will consider road conditions when selecting their speed of travel. This stretch of highway is fairly straight, provides good sight distance, and has few driveways and little roadside development. Drivers are complying with the current speed limit because they feel comfortable traveling at that speed given the existing road conditions.
Artificially lowering the speed limit on US 2 in Rice Road could have the unintended effect of increasing collisions. Some drivers would comply with the lower speed limit and others would not, resulting in a dangerous mix of slow-moving and fast-moving vehicles.
What about adding additional law enforcement resources to enforce a lower speed?
The solution is not to change the posted speed limit to an unjustifiably low speed and then expect law enforcement to control violators through constant monitoring. Our goal is to set realistic speed limits, based on the 85th percentile speed and roadway conditions. Realistic speed limits are better for drivers, better for law enforcement, and better for WSDOT. For more information, download our Speed Limits flyer (pdf 1 mb).
How do roundabouts compare to signalized intersections?
Studies have shown that roundabouts are safer than traditional stop sign or signal-controlled intersections.
There are several reasons why roundabouts help reduce the likelihood and severity of collisions:
- Low travel speeds – Drivers must slow down and yield to traffic before entering a roundabout. Speeds in the roundabout are typically between 15 and 20 miles per hour. The few collisions that occur in roundabouts are typically minor and cause few injuries since they occur at such low speeds.
- No light to beat – Roundabouts are designed to promote a continuous, circular flow of traffic. Drivers need only yield to traffic before entering a roundabout; if there is no traffic in the roundabout, drivers are not required to stop. Because traffic is constantly flowing through the intersection, drivers don't have the incentive to speed up to try and "beat the light," like they might at a traditional intersection.
- One-way travel – Roads entering a roundabout are gently curved to direct drivers into the intersection and help them travel counterclockwise around the roundabout. The curved roads and one-way travel around the roundabout eliminate the possibility for T-bone and head-on collisions.
How do roundabouts improve traffic flow?
Contrary to many peoples' perceptions, roundabouts actually move traffic through an intersection more quickly, and with less congestion on approaching roads. Roundabouts promote a continuous flow of traffic. Unlike intersections with traffic signals, drivers don’t have to wait for a green light at a roundabout to get through the intersection. Traffic is not required to stop – only yield – so the intersection can handle more traffic in the same amount of time.
While building a roundabout on US 2 at Rice Road will help simplify traffic flow through Sultan, it will not eliminate the congestion that drivers currently experience on the corridor. Drivers should still expect to see backups on busy holiday weekends and other peak travel periods.
Who can use a roundabout?
Roundabouts are designed to accommodate vehicles of all sizes, including emergency vehicles, buses, and truck and trailer combinations. We are designing this roundabout with a truck apron – a raised section of pavement around the central island that provides extra space for large vehicles. The back wheels of the oversize vehicle can ride up on the truck apron so the truck can easily complete the turn, while the raised portion of concrete discourages use by smaller vehicles. We are designing the roundabout to accommodate truck and trailer combinations up to 105 feet long.
Roundabouts are also safer for pedestrians and cyclists than traditional intersections. Crosswalks in roundabouts are set further back from traffic than traditional intersections, which means drivers can react to pedestrians and cyclists before they have to merge into traffic, rather than at the same time. Roundabouts also feature triangular refuge islands in the median, which means pedestrians and cyclists don't have to try to cross all lanes of traffic at once.
Why is WSDOT building a one-lane roundabout rather than a two-lane roundabout?
When designing a roundabout, we look at several factors to ensure that the roundabout will operate efficiently and safely. We analyze collision history, the types of vehicles using the intersection, how the intersection operates, and current and project traffic volumes.
We’ve looked at projected traffic volumes on this stretch of US 2 for the next 20 years, assuming substantial development in Sultan. A single-lane roundabout is appropriate for current and projected traffic volumes. A two-lane roundabout would provide too much unused roadway capacity, which could encourage risky and aggressive driving behaviors.
Want to learn more? Visit our Roundabouts page.