Dallas D2 subway would result in lower ridership and higher operating costs

The Biden Administration is developing a $3 trillion infrastructure plan, and every city wants in. That perhaps is the explanation for Dallas proceeding on a proposed downtown subway, because it certainly has no value-added for riders.

DART has 4 lines converging on a short segment running through a downtown transit mall. Two of those lines would be shifted a few blocks south to a new $2.7 billion subway. The plan does not provide any increase in service, except for the Red line which would see some additional peak-hour trains. DART concedes the project does not enhance service much. Indeed, the Build Alternative would see a net loss in transit ridership:

The main point of the project, according to DART, is to improve reliability and capacity. DART at one point looked at running trains on the branching lines with 10-minute headways, meaning 24 trains per hour through the downtown segment. That’s not exactly pushing the envelope; there are plenty of streetcar systems which achieve much higher throughputs. It is also curious that a subway is needed to improve capacity when DART runs just 2-car trains.

Computer simulation of subway stations. I lost count of the number of mezzanine and concourse levels at the Commerce station.