As with many currents in the flow of history, the industry is replete with choices that influenced events downstream. In this column, we’ll take a look at 10 technology choices that made the industry decidedly different. 1. Transit goes underground. There is no better statement about your city’s future shape than when you commit to taking your system below the streetscape. When Boston and New York built their subway systems in the early 20th century, it showed public transport’s ultimate potential. Decades later, Seattle demonstrated that the same concept works for buses, too. Boston listened, and today the Silverline has more passengers than any other BRT route. 2. Transit rediscovers traffic priority. The interurban construction boom taught us that transit can compete when given its own right-of-way. However, too often buses and trains share their routes with others. Even priority at signalized intersections has been a challenge. However, policy makers are rediscovering that bus and rail lines with priority over or separation from mixed traffic are cost-effective investments that score big market share gains. 3. The switch to buses. Whether you believe it was a cynical conspiracy, the perfect storm of bad choices or the inevitable result of technology’s march toward more output with less input (my theory), buses became the industry’s dominant vehicle by the mid-1950s. 4. Propulsion goes onboard. Beginning with rail’s switch to multiple units and the advent of motor buses, more of the industry’s fleet has become decentralized, and the change has created more operational flexibility and productivity. This will likely continue as U.S. cities join their counterparts abroad and begin to deploy modern diesel-electric cars. As buses go hybrid, could we see all modes in the same shop? 5. The PCC car vindicates standards. I have mentioned the decade-long effort to build a standard streetcar several times in this series already. With the American Public Transportation Association’s and other industry initiatives, are we finally ready to take the episode’s lessons to heart? 6. The little bus that could. One thing that Europeans envy America for is its extensive demand-response minibus systems. Dial-a-ride was put in place in the 1960s largely to address mobility needs of older and disabled populations. With computer-aided dispatching technologies, some cities use demand-response for much more, even to compete with the door-to-door convenience of cars. 7.Buses that bend in the middle. The 1970s brought rubber-tired articulated vehicles from Europe. Seattle in particular showed U.S. operators that higher-capacity transit didnt have to be on rails. The current bus rapid transit boom appears to agree as federal studies estimate two-thirds of this emerging segment will likely be artics. 8. Surface rail rediscovered. Calgary and Edmonton borrowed another lesson from Europe, that surface rail was still good for urban life, and with reliable, proven designs, it could be affordable. San Diego copied the blueprint, which became “light rail.” Today, nearly two dozen cities have such systems. While most projects in the New Starts project pipeline are light rail, some old-fashioned streetcar systems are also making comebacks. 9. Cleaner and greener. The Clean Air Act amendments in 1990 were bus transit’s marching orders to ever-cleaner emissions. All kinds of fuels have been experimented with, but the two finalists in the green race seem to be natural gas vs. clean-diesel hybrid, which face the same 2007 EPA emissions standards. Tougher standards are looking to force the issue on commuter rail soon, as well. 10. Can we go on a diet? Many of the above technologies make vehicles very heavy, which beat up roads and rails and consume tax and fare dollars in weight-related operating costs. Lighter composites have been introduced to LRVs and buses, but they are more expensive. Will this force the penultimate industry push toward life-cycle costing?