Interstate 90 is the only way on and off Mercer Island, and the I-90 bridges are already paid for. Any proposal to place a toll on I-90 must exempt those living on Mercer Island!
The technology exists to exclude MI residents from I-90 tolls. The tolling license plate scanners could compare the plate numbers of vehicles passing through the toll zone against a list of vehicles registered to Mercer Island residents. Any vehicle licensed to a Mercer Island residential address would not be charged. To qualify for this exemption, the owner of the vehicle must live on Mercer Island with a valid residential address.