For precisely the reason that Mayor Rob Ford and his brother Doug sing its praises, private enterprise is unlikely to participate in their plan to build a subway on Sheppard Ave.

To put it bluntly, it is a line that makes no sense. From a business point of view, this is a subway that can never hope to pay for itself, let alone turn a profit for its theoretical private-sector backers.

In the real world, if the price of construction weren’t enough to kill the subway, operating costs would be.

And rest assured, it will be taxpayers, mostly Torontonians, who will be stuck with the bill.

Were the Fords proposing a subway on Eglinton Ave, or the much discussed but ever distant downtown relief line, business’s response might be different. These routes have the numbers to justify a metro; Sheppard doesn’t.

Though supporters rightly argue the subway will generate greater densities, the process will require decades. Danforth Ave., for example, remains painfully undeveloped despite a subway that dates back to the 1960s.

As ruinous as the Fords’ transit ambitions may be, the history of political interference goes back a long way. Indeed, the existing Sheppard line remains a monument to how politicians confuse their own interests with those of the city.

Who can forget the Eglinton subway, one of the great transit fiascos of recent years? If you don’t recall: Construction on the Eglinton line actually got underway in 1994, one year before Mike Harris was elected premier and promptly killed the scheme. The hole had to be filled in — at a cost to taxpayers of $40 million.

We’re headed in the same direction today; in other words, still going around and around in circles.

Which brings us to Metrolinx, the provincial agency whose mandate is to plan and build transit in the Toronto region. Its role has yet to be fully determined, and in fact, it has more power than it has been prepared to use so far.

When the Metrolinx board meets Friday it will have a number of issues on its plate. Among them will be the question of the extent to which the organization should get involved in land planning around future stations. The intention would be to create density at these transit hubs through new zoning regulations.

The usual response has been to surround stations with acres of parking. A better approach might be to build the housing, retail and commercial facilities needed to support urban intensification as well as new transit lines.

If Toronto were Hong Kong, achieving density around transit hubs would be easy. Indeed, that would be the whole point of the exercise.

In Toronto, that’s not so clear. The Fords may prefer subways along Sheppard, but what about the people who live there? Would they choose the sort of mixed-use density that would follow the subway? As the Fords must also know, that’s unlikely.

The backdrop is the state of a city that was ripped apart by amalgamation but which has yet to put itself back together again.

As political as these issues of transit and density may be, they cannot be left to the vagaries of a system in which the new regime’s first task is to undo the work of the last.

If Metrolinx doesn’t take control, who will?

And while the Fords fiddle, the provincial government, which has pledged more than $8 billion for transit, faces an election in October. After that, no one knows whether the money will still be available.

Christopher Hume can be reached at chume@thestar.ca