1. Tolling is an extension of the time / money tradeoff that already exists in our transportation system. Setting the ideologically motivated aside, if one’s time is valuable in monetary terms, one usually drives; if one has more time than money, one uses transit. There are a few cases in the region where transit is actually faster door-to-door, but for the price-insensitive driving is almost always faster. Carpools exist somewhere in between: suffer the inconvenience of meeting up, but split the costs of driving.
Add in tolls, and the gap in cost increases, while both modes get faster. While the marginal bus/car traveler may shift to the bus, those dedicated to their mode and interested in getting somewhere as fast as possible are big winners. Indeed, if the marginal bus/car traveler didn’t shift modes or abandon the trip, reducing congestion would be impossible.
2. It follows that no one on Mercer Island will be “cut off” as long as inexpensive bus service exists on Mercer Island.
3. One of the more potent arguments against tolling is that it is regressive. Personally, I see no other practical way to ration the road space. Nevertheless, what would clearly make the policy worse would be to exempt the city with the highest median household income in or near the I-90 corridor.
4. Some have expressed angst on behalf of the service workers who commute to Mercer Island. If it’s no longer economic to commute there, wages will inevitably rise. If that isn’t satisfactory, a targeted way to assist service workers in the new regime would be to use a sliver of the new toll revenue to ensure excellent transit coverage on Mercer Island. From a policy and fairness standpoint, that is a vast improvement over exempting some of the region’s wealthiest residents for what amounts to a corner case.