- How do the blades of a jet engine start turning?
- Is there a way to detect my car’s keyless remote if I don’t know where it is?
- What are the future propulsion systems for interplanetary travel?
- How can a person ride a motorcycle 100 mph but not stand up in a 100 mph wind?
- Why does traffic bottleneck on freeways for no apparent reason?
- Can a honeybee cause a sonic boom if it travels fast enough?
- Can helicopters fly upside down?
- Why don’t spacecraft burn up or veer off course during reentry from space?
- Can robotic submarines collect specimens at any ocean depth?
- How does a jet engine work?
Will public transportation ever replace the automobile?
Maybe, but probably not the public transportation we’re used to…By Elizabeth Dougherty
We are probably moving toward increased use of public transportation, says Amedeo Odoni, professor of aeronautics and astronautics and civil and environmental engineering, but he isn’t talking only about subways and buses. “I mean a much more flexible and integrated public transportation system than we have today,” he says. For example, Odoni and his fellow researchers on the Future of Urban Mobility Project in Singapore are developing a hybrid system that combines the agility and convenience of private cars with the shared costs and shared vehicles of a public system.
The vehicles themselves may also be more flexible. Instead of SUVs and sedans, MIT’s Smart Cities project is designing electric cars and scooters that can fold up to maximize the capacity of existing parking spaces and that are maneuverable enough to turn parallel parking and K-turns into distant memories. The key concept, however, is mobility-on-demand, where urban travelers share pools of vehicles rather than owning them privately.
Small-scale versions of mobility-on-demand already exist (think of pools of Parisian bicycles), but a trend away from private vehicles has yet to take off. In fact, in many parts of the world, car purchases are ramping up. A World Business Council on Sustainable Development report in 2004 projected that the number of vehicles on the road in Asia will double between 2000 and 2025.
Strategies for limiting the use of private vehicles — or encouraging the use of public resources for transportation — vary a great deal. In Singapore, you cannot just go out and buy a car, Odoni notes. To buy a car you need to bid for the right to do so. This right currently costs close to $30,000 — more than the cost of many new cars in the US.
Such limitations on car ownership would not be politically feasible in the US, says Odoni, but “fees and tolls may discourage the use of private automobiles in central parts of some of our major cities.” He points to a new effort in London where the city began charging for inner-city road use during high-traffic hours. Many U.S. highways and bridges have tolls that increase in urban centers. And in 2009, California began taxing emissions. “I think we are moving in this direction,” he says.
The last holdouts on the demand for private cars will likely be outside the city, Odoni says. “It all depends on the particular environment — how much traffic, how many people, and what their needs are.” In some cities, what may work best is a combination of scheduled mass transit and mobility-on-demand. In the not-too-distant future, the latter may even utilize fleets of driverless electric cars or shared-use bicycles that can somehow show up when and where they’re needed.
Posted: March 15, 2011