Setbacks in attempts to launch urban rail projects over the past two decades have apparently led top San Antonio officials and planners to scratch rail off the city’s agenda. The officially backed ConnectSA “Proposed Framework” for “Modern Mobility,” for example, bets the city’s mobility future on a bus-focused system, with “advanced” bus rapid transit, or BRT, running battery-electric buses as its centerpiece.

That’s a big mistake.

Given its demographics and growth rate, San Antonio needs urban rail transit as urgently as it did in 2000. And lower-cost light rail transit, or LRT, technology is an affordable and compelling option with a solid record of achievement.

Consider Charlotte, N.C., with less population and lower density than San Antonio. Nevertheless, with its own half-cent tax, the Charlotte Area Transit System managed to open its Lynx LRT system in 2007 and has built 20 miles of line. Over a 12-year period, total fixed-route ridership increased 42 percent while operating cost per passenger mile (adjusted for inflation) dropped 7 percent.

But doesn’t BRT offer “transit service that has the benefits of light rail, without the need for tracks,” as ConnectSA promises? If that were true, it’s unlikely that Ottawa would be spending several billion dollars converting the largest BRT network in North America into a new LRT system.

A similar case in point is Seattle, which — to bolster capacity — has just expelled BRT from its downtown transit tunnel, converting to an exclusive LRT operation. And why have peer cities such as San Diego, Portland, Sacramento, Dallas, Houston, St. Louis, Denver, Salt Lake City, Phoenix and Minneapolis all invested in LRT, rather than BRT, as the cornerstone of their revitalized transit systems?

Crucial functionality is part of the answer. Light rail transit excels in the ability to grow with urban growth, moving large volumes of passengers efficiently and cost-effectively. Public preference for urban rail is well documented, and LRT leads in attracting new riders (especially from cars) with better performance than buses, as well as comfortably handling ridership surges and incremental growth with greater capacity. A performance analysis of new-start LRT vs. BRT systems (from data reported in the federal National Transit Database) indicates LRT carries 2.7 times the ridership of BRT at 9 percent lower operating cost per passenger mile.

And while LRT’s initial capital cost may be higher, the greater capacity potential tends to pay off in the longer term. Light rail transit vehicles have two to three times the life of buses (including electrics), as well as several times the passenger capacity. In addition, some LRT infrastructure components surpass the economic life of BRT (e.g., steel rails vs. pavement).

But perhaps at least as compelling a benefit is the tendency of light rail projects to catalyze economic development. While several BRT projects have seemed to act as a supplement to attracting or reinforcing a proportion of such development, LRT projects have catalyzed development near stations on a multibillion-dollar scale.

Examples include Dallas, $11.6 billion; Portland, $20.7 billion; Salt Lake City, $7 billion; Minneapolis-St. Paul, $8.4 billion; Phoenix, $11 billion.

Such economic impacts not only generate more ridership from residential units and commercial activity, but in addition — particularly by expanding tax base — they produce a revenue stream that can help fund the transit project.

Civic and transit leaders would be unwise to ignore these potential benefits, or to assume the same could be achieved with lower-grade investment in BRT. VIA’s Primo “light” BRT, for example — while clearly an improvement in bus service — so far has had zero impact on development near stations.

Light rail is neither a silver bullet nor a panacea, but it’s a mode with sufficient capacity, public support and performance qualities to help “future-proof” San Antonio’s mobility. We know it works, and it’s available “off the shelf” now.

However, this also requires a commitment to more progressive land-use measures and a truly comprehensive, multimodal grid of transit and other mobility alternatives. San Antonio’s dollars-per-capita transit investment is only a fraction of its peer cities — compared with Houston, just 61 percent; Austin, 48 percent; Dallas, 39 percent. This needs to improve, and, in addition to reconsidering LRT, many of the ConnectSA recommendations are a good place to start.

Lyndon Henry is a transportation planning consultant and former board member of Capital Metropolitan Transportation Authority in Austin.