One of the major roadblocks to increased mass transit ridership in the US is classism--specifically, the perception that buses are for the lower classes. I have plenty of friends that rely heavily on other aspects of the local transit system, but have never set foot on one of its buses. Many cities, realizing the positive public impression of rail transit, have begun restoring streetcar routes in hopes of enticing a wider rider base.

Streetcars offer many sustainability advantages over buses. Their steel wheels last longer and are infinitely easier to recycle than the rubber treads on buses. Streetcars are also run almost exclusively on electrical power, which produces no carbon, smog-forming, or particulate emissions in the immediate vicinity of the streetcar, and can be generated from renewable sources.

However, streetcars also have shortcomings. Traffic snarls have far more potential to entangle streetcars, as unlike a bus, the streetcar cannot simply steer around a double-parked car. Streetcars also require riders to wait curbside in often inhospitable conditions, a far cry from the relative comfort of a subway station. And accessibility issues for reduced-mobility riders often plague restored rail car routes, many of which still use built-to-last rolling stock from the 1930s.

Despite their shortcomings, streetcars could be a valuable part of a city's transportation infrastructure, stimulating nearby businesses as a tourist attraction and providing a high-visibility reminder of the availability of mass transit.