A report sent to the governor about tolling to replace the SR-520 bridge showed that most drivers polled agreed that the aging bridge needed to be replaced and paid for by tolling. It was less clear from the results if both bridges should be tolled and what the impact would be on driver behavior as a result.

The 520 Tolling Implementation Committee report was conducted by Bob Drewel, executive director of the Puget Sound Regional Council; Washington Transportation Secretary Paula Hammond; and Washington State Transportation Commissioner Richard, “Dick,” Ford.

The committee was charged with evaluating tolling for financing the 520 bridge replacement and HOV program, engaging citizens and regional leadership in the evaluation, enhancing understanding of tolling alternatives, and reporting back to the governor and the Legislature this month.

Along with an extensive outreach effort contacting some 16,000 people in the region, the committee conducted a pair of surveys to gauge the public’s reaction to tolling to replace the bridge. The report indicates that the majority of those asked supported tolling I-90 in addition to SR-520, but that there was strong opposition from I-90 users.

A scenario analysis found that with tolls in place, traffic volumes decrease and speeds improve and, when tolling is in place, drivers will change their behavior: by selecting a new route, taking transit, changing the time of day when they drive or choose not to drive. Most, however, not an overwhelming majority, will pay the toll and support some sort of time of day or variable pricing.

Some 8,000 people, 60 percent of whom were male, took the Web survey last November. Sixty percent of respondents were between 25 and 44 years old. Half said that they use SR-520 regularly, while one quarter indicated that they regularly travel on I-90 to cross the lake. The online survey, indicating that commuters would choose I-90 as an alternate route if 520 was tolled, has many Islanders concerned. But many who might choose I-90 over SR-520 on any given day could be drivers who regularly make that their preferred route.

Just under half of all 1,200 respondents who took the online survey said that when they took the bridge they ordinarily chose SR-520, leaving 26 percent who generally take I-90 bridge or 19 percent who “equally use either bridge.” In a question worded differently than the online survey, between 8 and 11 percent said that they would take another route if tolls were in place on 520.

Notable is how many people took the time to participate in the surveys who apparently do not commute. The telephone survey included 400 respondents or one-third who did not use either bridge regularly. Of the number of online respondents, nearly one quarter said that they had not crossed either bridge even once in the week before they took the survey; and 18 percent said that they had crossed the bridge just once. In both surveys, at least two-thirds of those crossing drive alone in a car.

Respondents in both surveys supported tolling 520, and tolling sooner rather than later in order to lower costs for future construction. When asked if they would prefer tolling both bridges to lower tolls on both, the majority, not surprisingly, said yes. Respondents also said that they would want lower tolls for off-peak use and weekends.

Of the more than 5,000 written responses or comments made within the survey or at meetings, nearly one-half were from Mercer Island residents.

The stated error for the telephone survey was plus or minus 3 percent. Since participants in the online survey are self-selected, those results are not statistically valid. Instead, that survey was to offer another way for residents to give input. Results from the online survey were similar to that of the telephone survey.

For more information, go to build520.org.