Those who are against tolls on the I-5 and I-205 bridges often argue that what is needed to reduce congestion is more bridges over the Columbia River. While this seems good in theory, it is not as plausible as it seems.
If a new bridge were to be added upstream, not only would local businesses on both sides of the river be wiped out, but the connection would cut through Fort Vancouver National Historic Site, requiring an act of Congress to secure the land. Moving downstream would cut through downtown Vancouver, again obliterating more homes and local businesses. Farther up or downstream and you run into problems with PDX airport and Pearson Airfield.
As far as tolls are concerned, the only people who would be affected are those using the bridge and interstate. It costs money to build/ maintain bridges and roads, and that money must come from somewhere. A toll is a way to generate these funds without raising taxes. A toll might also encourage those who routinely drive to Oregon to shop to buy locally, supporting our local businesses and economy.