But this is besides the point. The freeway itself gobles up land upon which taxes were once paid and now are not. The extent of development caused by freeways vs. overall development that would have occurred anyway is probably negligable. Most freeway miles are through rural areas (thus, less taxable farm and forest land in relatively poorer rural districts).
Your argument is still fallacious. For starters, freeways already exist in most urban areas and were built there long before those properties were valuable. Second, the ammount of freeway mileage in downtown is a tiny fraction of the freeway mileage in any major city, with the vast majority of it existing outside of downtown and in areas where those supposed properties do not exist. Third, when freeways are built they normally emerge in the place of or on top of an existing road that was never on your precious tax roles to begin with. When all things are considered, the loss in property taxes from freeway expansion is (1) offset by the growth of commerce around the freeway, (2) so small to begin with that it is not of significant matter, and (3) virtually negligable in comparison to the costs of rail. In short, you are picking at the speck while ignoring the log.
In the suburbs, properties abutting the freeway, if already developed, also lose value because of noise and pollution.
That's why you build a sound wall.
The freeway itself gobles up land upon which taxes were once paid and now are not.
To a negligable degree. And for the record, your precious rail does the exact same thing...or do they lay the tracks on top of the telephone pole wires?