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tolling scenarios
520 bridge

The Committee's role is to evaluate possible toll rates to learn about revenues, traffic effects, diversion and potential mitigation measures. These are scenarios, not recommendations, and are for analysis and comparison purposes only. The Committee reported all of its findings to the legislature on January 28, 2009.

Want to know what people told us about tolls? See these reports:

All toll rates are example toll rates for planning purposes. Actual toll rates will depend on a final finance plan and will be set by the Washington State Transportation Commission with approval by the State Legislature.

All rates below are in current year dollars and will be adjusted for inflation if implemented.

Want to dig into the details of the data?

Staff note: On March 17, 2009, staff updated numbers related to toll rates. Updates were made to correct inadvertent errors in toll rates shown under Scenario 7 in 2010 (evening), correct the overnight rate under Scenario 2 (2016), clarify segment toll rate under Scenario 6 (2010) and to provide clarification that tolling will not begin until 2016 under Scenario 5. We apologize for any confusion.

Toll Rates
  1. Under these scenarios, what would it cost to use 520?
  2. What is the highest round trip toll evaluated?
  3. What is the lowest toll evaluated?
  4. Were weekend tolls evaluated?
  5. How does the average toll rate compare to the historical toll rates on SR 520?
Traffic and Diversion
  1. How would tolling SR 520 affect traffic speeds?
  2. Why does variable tolling change speeds?
  3. If traffic goes down when a road is tolled, where do those people and their cars go?
General tolling questions
  1. Would I pay a toll if I use 520 but don’t cross the lake?
  2. Will tolls be implemented on I-90?
  3. Would carpools and transit pay a toll?
  4. Could tolls on I-90 be used to pay for 520?
  5. How would tolls be collected?
  6. Will tolls be removed when the bridge is paid for?
  7. Will toll revenue be used to fund transit?
Process and Decision Making
  1. Who gets to decide what the toll will be?
  2. Some of this data looks different – is it?
Under these scenarios, what would it cost to use 520?
Average Toll

The average toll paid was estimated between $1.70 and $2.36 for all 2010 scenarios evaluated (with no tolls collected overnight). The average toll paid for 2016 scenarios, was estimated between $1.64 and $2.92. These are one-way, in 2007 dollars and do not account for inflation.

Variable Tolls

Most of the toll rates evaluated are variable, so what you pay depends on when you travel. People who travel during the busiest times of day would pay the highest tolls while people who choose to travel at less busy times of day could take advantage of lower tolls.

Below is a range of toll rates considered, by time of day:

Morning commute (5 am – 9 am)$2.15 to $4.25
Mid day (9 am – 3 pm)$1.05 to $2.75
Afternoon commute (2 pm – 7 pm)$2.80 to $5.35
Evening (7 pm – 10 pm)$1.00 to $2.60
Overnight (10 pm - 5 am)$0.00 to $0.90
Weekends$0.80 to $1.60
Flat Rate Toll

One flat rate toll was evaluated: $1.70 regardless of time of day or traffic conditions.

What is the highest round trip toll evaluated?

People who travel during the busiest times of day would pay the highest tolls. Under the scenarios evaluated, the following would be the highest round trip tolls:

On 520
  • In 2010, that would be $6.85 ($3.05 in the morning and $3.80 in the afternoon).
  • In 2016, the highest round trip would be $9.60 ($4.25 in the morning, and $5.35 in the afternoon).
On I-90
  • In 2010, the highest round trip toll evaluated for I-90 would be $5.85 ($2.60 in the morning and $3.25 in the afternoon).
  • In 2016, the highest round trip toll on I-90 would be $4.90 ($2.30 in the morning and $2.60 in the afternoon).
What is the lowest toll evaluated

The lowest toll rates evaluated occur during the least busy times of day. Examples of the lowest one-way toll rates are shown below. Round trips are not calculated because round-trip travel times are more variable outside of traditional commuting times.

On 520
  • In 2010, no tolls would be charged overnight (11 pm to 5 am).
  • The lowest rate evaluated for 2010 is $1.00 each way (between 5 am and 6 am, and between 9 pm and midnight).
  • In 2016, the lowest toll rate evaluated is $0.75 each way (overnight and early morning).
On I-90
  • The lowest rate evaluated for 2010 is $1.00 each way (between 5 am and 6 am, and between 9 pm and midnight).
  • In 2016, the lowest toll rate evaluated is $0.75 each way (overnight and early morning).
Were weekend tolls evaluated?

Yes. On weekends, tolls evaluated ranged between $0.80 to $1.60, depending on what time you drive.

How does the average toll rate compare to the historical toll rates on SR 520?

The initial, one-way toll on the SR 520 Bridge, in 1963, was $0.35. The toll was taken off the bridge in 1979. Today, a $0.35 toll from 1963 would be $2.48 after inflation. A $0.35 toll from 1979 would be $1.05 today.

How would tolling SR 520 affect traffic speeds?

On 520, speeds could increase up to 40%, to between 10 and 30 mph. The only time speeds would decrease on I-90 by more than 5 mph is under the highest toll scenario for 520. With two-bridge scenarios, speeds increase on 520 and I-90 in both peak and off-peak times.

On 522 and 405, speeds don’t go down more than 3 mph.

Examples: 520 bridge speed ranges in 2010; speeds with tolls, compared to roadway speed without tolls
Why does variable tolling change speeds?

When a road is tolled, fewer people will drive on it. With fewer cars, speeds go up. If only 520 were tolled, traffic volumes on I-90 would increase between 3 and 8 percent during peak travel times. If both bridges were tolled, volumes on I-90 would decrease, allowing traffic on I-90 to move at faster speeds

520 bridge speed ranges, comparing no toll, flat toll and variable tolls in peak times in 2010. Off-peak speed increases could be up to 30 mph.
If traffic goes down when a road is tolled, where do those people and their cars go?

There are several choices for people who don’t want to pay a toll. They can ride transit, drive on another route, change the time of day they travel to reduce the toll, or choose a different destination (such as a destination that does not require a lake crossing). The November evaluation found that:

  • Transit ridership on 520 could increase 15 to 35%, if transit service is in place.
  • Traffic on I-90 could increase less than 5%, except in the highest toll one-bridge scenario (8%).
  • Traffic on 522 would increase 5% or less.
  • Peak period diversion to I-405 at 167 would be greater in two-bridge scenarios, with volume increases reaching 8%.
  • Local roadways leading to tolled bridges would have less traffic when tolls are in place.
  • Between 2% and 11% would move from peak to non-peak travel times.
  • Under one-bridge scenarios, 0-15% of drivers change their destination.
  • Under two-bridge scenarios, 3-10% of drivers change their destination.

Examples of traffic diversion when tolling 520
(2010, Scenario 7: Toll 520 in 2010, increase rate in 2016)


Example of traffic diversion when tolling both 520 and 90
(2016, Scenario 9: Toll both bridges in 2016)
Would I pay a toll if I use 520 but don’t cross the lake?

Some of the initial scenarios featured tolls on segments of the highway (such as I-5 to Montlake) that will be improved as part of the project. However, public feedback from people and governments on both sides of the lake indicated that these “segment” tolls are not supported. The legislature will make the final determination on where tolls will be collected.

Will tolls be implemented on I-90?

The legislature asked the Tolling Implementation Committee to look at tolling I-90 as a way to help fund the 520 project and to pay for improvements to I-90 as well. If the state decides to pursue tolling I-90, both the Federal Highway Administration and the State Legislature would need to approve it.

Would carpools and transit pay a toll?

The Washington State Transportation Commission will determine if carpools and transit pay a toll.

Some scenarios assumed that neither transit nor carpools with three people would pay a toll. One toll scenario (Scenario 6) evaluated would charge tolls to transit and carpoolers. The intent was to determine if a high-toll one-bridge scenario could raise enough funds to build the bridge.

Could tolls on I-90 be used to pay for 520?

Four scenarios assumed tolls are placed on I-90. For planning purposes, these scenarios assume approximately $100 million of the revenue would go toward adding two-way transit and HOV lanes to I-90. . Other funds beyond $100 million were assumed to be available for 520. The use of toll revenue will be decided by the legislature.

How would tolls be collected?

Tolls would be collected electronically. If you have a Good to Go! transponder you would be able to use it on 520, the Tacoma Narrows Bridge and SR 167 HOT lanes. Drivers without a transponder would have their license plates read and pay by phone or on-line. If the toll is not paid promptly, a bill would be sent in the mail to the vehicle owner, including an administrative fee for collecting the toll.

Will tolls be removed when the bridge is paid for?

The legislature will determine whether tolls are removed when the bonds for the facility are paid off or whether some level of tolls remain to pay for operations and maintenance and repair of the bridge.

Will toll revenue be used to fund transit?

The Committee heard differing views from individuals and jurisdictions on whether a portion of the toll revenue should be used to support increased transit service in the corridor. While allowed by law, the final determination will be made by the legislature.

Who gets to decide what the toll will be?

The actual toll rates will depend on a final finance plan and will be set by the State Transportation Commission with approval by the State Legislature.

Some of this data looks different – is it?

Updates were made in two areas after the release of the November Scenario Evaluation on November 10, 2008. Specifically:

  1. Bridge funding final estimates. Several of these scenarios were updated to reflect ongoing refinements made by the State Treasurer’s Office to the original estimates. In some cases, this means that bridge funding estimates are higher than originally reported; in others, lower.

    Specifically, on the 520-only flat rate toll scenario (Scenario 5), initial cost estimates have been updated to reflect final numbers received from the Washington State Treasurer’s Office, which were much lower than originally reported. These indicate that approximately $522 million could be gained from flat-rate tolls beginning in 2016 ($654 million originally reported).

  2. Average toll paid. Under Scenario 1, average toll paid was inadvertently originally published as “$1.64” when tolling begins in 2016. The correct figure for average toll paid is $2.28.