If 90% of commuters buy EVs you would expect to have economies of scale start to kick in, hopefully reducing the cost of the EV down to the cost of more traditional econoboxes which should offset the loss of government subsidies. You are most likely correct on the tolls and car pool access going away.
If you really want to compare apples to apples, eliminate the subsidies on petroleum and then compare because all those external costs need to be factored into gas costs, you know the cost of the military keeping those shipping lanes open.
Not an EV owner yet but seriously considering for my next commuter vehicle. 50 miles round trip should provide a decent pay back period.