Sometime in the next few weeks — or months, since the District government now refuses to offer a hard start date and has recently suffered a technical setback — the H Street Corridor Streetcar will begin its regular service of congesting traffic and slowing existing bus routes.

City officials dream of an extensive streetcar network eventually linking transit-poor neighborhoods into D.C.’s fairly impressive public transportation infrastructure. Unfortunately, the streetcar is a legacy technology, far more costly to implement than equivalent bus service. The likely failure of this line will be a black eye for transit advocates, in yet another setback for thoughtful public investment in transit.

There’s nothing wrong with the idea of dense, transit-oriented development. Strong transit supports a pleasant, walkable environment, which is both an amenity and an obesity fighter; compact development uses less land and reduces the environmental impact of growth; urban density raises wages by boosting labor productivity; public transit networks are less congestible than automobile networks, allowing a city to grow beyond what’s possible with cars alone; and so on and so forth.

Yet this streetcar still isn’t a good idea. The H Street corridor lacks a dedicated lane, trapping the streetcar in the same vehicle congestion that the X2 bus deals with (and, based on pre-revenue testing, snarling traffic and slowing the buses even more). It is functionally a more expensive bus with less route flexibility and no ability to bypass illegally double-parked cars or other obstacles.

Indeed, rail-quality bus stations and higher frequency service—the first available steps in a system closer to the Orange Line Bus Rapid Transit in Los Angeles, even if the Virginia Department of Transportation won’t yet permit a dedicated lane—are cheaper and more flexible than streetcar installation, yet they serve the same quality and capacity goals.

The potential for even marginal usefulness of the H Street streetcar venture is a bet entirely on an uncertain, costly future expansion of the streetcar network. In the meantime, transit opponents will mock the latest boondoggle stub line of a streetcar (and not without reason). Imagine their schadenfreude at the plight of X2 bus riders trapped behind an empty streetcar running constant budget deficits.

Even as D.C. awaits the start of normal service on this new line, the Washington Metropolitan Area Transit Authority is pondering service cuts and fare hikes on subways and buses in the current budget. The time between rush hour trains on the Metro could rise from the current 6 minutes to 8 minutes, and late-night weekend service could be cut entirely.

It is madness to attempt to bootstrap a less cost-effective, marginal transit network when regional transportation officials already struggle with out-of-control costs on the existing core network. Should the city shore up the transit authority and improve bus service to complement the Metro system and bolster ridership? Absolutely. But the addition of a low-ridership boondoggle to the region’s infrastructure will only weaken voters’ confidence in the government’s ability to prudently manage and invest in transit.

As Kriston Capps wrote at Citylab, “The problem with this Streetcar line is that it takes people from where they aren’t to where they don’t need to go.” It’s a stub line less useful than the bus service already serving its territory. It is worse for riders than bolstering the existing transit network, with its only advantage being nostalgic indulgence. This reality implies it is geared more to tourists than to commuters and residents. Serious transit advocates should reserve their credibility for cost-effective improvements to the existing bus and rail networks and avoid the inevitable blowback against yet another wasted opportunity for prudent public investment.

This piece originally appeared in Washington Examiner