I-405 Congestion Relief and Bus Rapid Transit Projects - Project FAQs

Why does I-405 need to be improved in the first place?

  • I-405 commuters face the worst traffic congestion in the state – up to 10 hours a day in some locations.
  • I-405 is the second-most traveled corridor in Washington State.
  • I-405 is the only high-capacity north-south route on the Eastside. Some 800,000 trips are made on I-405 everyday.
  • Users of I-405 are well aware of the problem – nearly half of respondents to a recent WSDOT survey rated I-405 traffic congestion as very serious; about half also said they regularly change their plans or go out of their way to avoid I-405.
  • The cost of delay in the I-405 corridor—lost time and wasted fuel—is calculated at $930 per person per year.
  • Congestion results in unpredictable travel times, fewer productive work hours, increased personal stress and a high rate of side and rear collisions. And, as a vital link in our regional transportation network, a highly congested I-405 is a deterrent to economic growth.
  • I-405 carries twice the amount of freight shipped each year through the Port of Seattle.


What is the Master Plan for I-405?

  • In October 2002 the federal government released a Record of Decision approving the I-405 Environmental Impact Statement. This document is a Master Plan for regional transportation improvements on the Eastside.
  • This corridor-wide programmatic planning document was the result of unprecedented cooperation between all the cities, legislative leaders and agencies in the I-405 corridor.
  • Major pieces of the Master Plan include:
    • Adding up to two new lanes in each direction for the entire 30-mile length of I-405.
    • Developing a bus rapid transit line with stations along I-405 and expanded transit centers.
    • Improving key arterial streets.
    • Creating 1,700 new vanpools – a doubling of the region’s current fleet.
    • Building 5,000 new park-and-ride spaces.
    • Building eight new pedestrian/bicycle crossings over the freeway.
    • Increasing local transit service by 50 percent.
    • Adding a managed lane system.


What are the benefits of the Master Plan?

Ultimate benefits of the Master Plan include:

    • Accommodating an additional 110,000 trips per day.
    • Reducing time stuck in traffic by more than 13 million hours per year – an average of more than 40 hours a year for each regular user of I-405.
    • Producing travel time savings valued at $569 million a year.
    • Removing chokepoints and weaving traffic movements will improve safety by reducing side and rear collisions.
    • Enhancing freight mobility with better interchanges, travel time savings and updated technologies.
    • Providing economic benefits through construction. Each $1 billion spent on transportation construction generates 47,500 jobs, according to the USDOT.
    • $5.40 returned to the economy in congestion savings for each $1.00 invested in highways , also according to the USDOT.


How long will it take to complete the Master Plan?

  • The Master Plan is a 20+ year roadmap.
  • In October 2003, the I-405 Executive Committee approved a medium-term Implementation Plan with $4.7 billion worth of projects that could be built over the next 10-15 years.
  • A set of implementation principles were developed to guide selection of projects. These are:
    • Fulfill the long-term vision.
    • Address the worst chokepoints first.
    • Enhance environmental quality.
    • Improve livability for our communities.
    • Support a vigorous state and regional economy.
    • Accommodate planned regional growth.
    • Implement early environmental improvements when possible.
    • Minimize overall costs and risks.
    • Minimize construction impacts.


How much will it cost to fix I-405?

  • $485 million in projects funded for I-405 with the 2003 Nickel Program from the Legislature.
  • Another $972 million for 11 projects funded by the 2005 Transportation Partnership Account passed by the Legislature.
  • The long-term Master Plan, if realized, would total and estimated $10.9 billion (2002 dollars) in transportation and transit improvements.


How much new capacity is being added with I-405 projects?

The Nickel Projects added 18 new lane miles of roadway on the mainline freeway, one new lane mile of ramps, and one-half mile of new local roadway, for a total of 19.5 new lane miles.

The TPA projects added 15.3 new lane miles of roadway on the mainline freeway, six new lane miles of ramps and two miles of new local roadway, for a total of 23.3 new lane miles.


Are I-405 projects on time? On budget?

  • Yes. We have delivered 13 projects on time and on budget.
  • A major reason why I-405 projects are ahead of schedule is the use of the design-build process, which allows a joint engineering/construction group to finalize designs for the roadway while they begin construction. In the past, projects were completely designed by WSDOT before contracts were let for construction. The design-build process, rapidly being adopted around the nation, saves time and provides for innovative solutions to design and construction issues. A principal benefit is getting projects into service as quickly as possible to reduce congestion and improve safety for all users.


Isn't I-405 just a big roads project?

No. The I-405 Program provides a variety number of improvements that benefit users of carpools, vanpools and transit in addition to single-occupant vehicles and freight users. For example:

  • Improvements at all three Nickel Project locations on I-405 are designed to reduce congestion caused by weaving traffic and the reduction of lanes, which cause bottlenecks. These changes will benefit all users.
  • Improvements in both the short- and long-term will help maintain and even improve travel reliability for HOV lane users, 80 percent of whom commute in car- and vanpools.
  • The Sound Transit-funded Totem Lake Freeway Station/HOV direct access ramp now under construction at NE 128th Street in Kirkland will benefit not only transit and HOV users, it will reduce weaving caused by vehicles merging to the HOV lane, which improves traffic operations for motorists in the general purpose lanes. This project will also take pressure off the NE 124th Street interchange as HOV users and transit vehicles will use the NE 128th access instead.
    • The Bellevue Downtown Access HOV ramp at NE 4th Street, opened in summer 2005, provides similar benefits.
    • Although unfunded at present, an HOV direct access ramp at NE 8th Street in Renton is part of the long-range plan.
  • The I-405 Master Plan calls for a system of managed lanes along the length of the corridor. This would essentially be a double HOV lane in each direction. Pending results of a WSDOT study on High Occupancy Toll, or HOT, lanes, all or a portion of the corridor’s managed lane system could allow for single-occupancy vehicles to “buy in” to unused capacity in the HOT lanes. This would only be done as long as operations for transit and HOV users would not be compromised.
  • The I-405 Master Plan calls for a doubling, to 1,700, of vanpools in the central Puget Sound region, a 50 percent increase in local transit service, the addition of 5,000 new park-and-ride spaces and the building of eight new pedestrian/bicycle crossings over I-405. These amenities will be phased in as budget allows.
  • Plans are being made for the addition of a bus rapid transit (BRT) line along I-405. This would provide frequent bus service along the freeway, connecting with transit centers in urban centers, such as Bellevue, Kirkland, Redmond, Renton and Tukwila.


What is BRT?

  • Bus rapid transit, or BRT, is similar to light rail transit except that it uses rubber-tired buses specially built for the purpose. BRT, which is used throughout Latin America and is becoming popular in large U.S. cities, has several characteristics that are different than regular bus service, such as:
    • Fewer stops and generally higher speeds.
    • Off-vehicle fare collection. Users buy tickets or use passes at stations, rather than on the bus.
    • Distinctive-looking, low-floor buses similar to light rail vehicles.
    • The flexibility of BRT allows it to use dedicated busways, HOV lanes or mix with general traffic.
    • When used on arterial streets, BRT often makes use of a signal-priority system to allow the buses a “head start” at green lights.
  • Because of their flexibility and relative lower cost, compared to light rail and other fixed-guideway systems, BRT is being implemented in cities across the country, including Los Angeles, Boston, Washington, D.C., Cleveland, Honolulu, Miami and San Jose. 


What are the environmental aspects of the I-405 project?

  • Our overarching environmental goal: Leave the environment better than it is today. We will do this by:
    • Restoring natural stream flow and removing stream blockages.
    • Improving salmon habitat.
    • Approaching mitigation from a holistic watershed view.
  • The I-405 team is committed to begin environmental investments as early as possible in the construction process to maximize positive effects on the watershed.
  • WSDOT’s environmental approach is to target environmental improvements to areas that have the greatest long-term environmental benefit, as opposed to just providing short-term spot treatments.
  • Environmental mitigation for the Kirkland Nickel Project included: stormwater facilities to provide detention and water quality treatment; three wetland mitigation sites; stream protection and fish passage culvert replacement at Forbes Creek; construction of five new noise walls; and relocation of four existing noise walls.


What environmental process has the I-405 project followed?

  • As with other proposed transportation projects, the I-405 program has followed the requirements set forth under the state and federal Environmental Protection Acts.
  • A three-year Environmental Impact Statement/programmatic planning process for the entire 30-mile I-405 corridor was completed in 2002. The federal government signed off on the EIS with a Record of Decision in October 2002.
  • In addition to the programmatic EIS, a further level of environmental review is required for individual construction projects on the corridor. For example, an Environmental Assessment (EA) was completed for the Kirkland Nickel Project, which begins construction at the end of 2005. EAs are also underway for the Bellevue and Renton Nickel Projects.


What can I expect during construction?

  • WSDOT is working to minimize inconveniences to motorists during highway construction with up-to-date information about traffic and travel options.
    • Construction updates and traffic information for all projects can be found by visiting our construction updates page.
    • Travel options include finding alternate routes to avoid the construction zone, riding the bus or using a vanpool, modifying your work hours to avoid the worst congestion times, or telecommuting when possible.