A 2003 General Motors concept car on display at the Test Track attraction at Disney World's Epcot.

Future car technologies include new energy sources and materials, which are being developed in order to make automobiles more sustainable, safer, more energy efficient, or less polluting.

Main energy sources

Andrew A. Frank argues that hybrid cars that can be plugged into the electric grid (plug-in hybrid electric vehicles) will soon become standard in the

• dual mode vechicle or vehicles able to platoon that use relatively small electric motors and fuel supplies or battery reserves for door-to-door service off electrically powered arteries. Some swap battery packs to avoid waiting associated with recharging. This also avoids deep discharge that shortens battery life and makes a smaller and lighter battery pack with logistically infinite range using incremental energy sipping through frequent fully automatic battery exchange at speed. The monorail mode provides superior safety at very high speed.

• battery electric vehicles have the potential of using locally available sustainable energy resources while at the same time reducing vehicle energy requirements by 1/2 to 1/4 when using batteries to store electricity. A new high-performance electric sports car, the Tesla Roadster has attracted much media attention^[1] since its release in June 2006.

• hydrogen cars could eventually be produced that use sustainable energy resources and water. The resulting hydrogen could be burned in an engine or converted back into electricity by a fuel cell and its support systems instead of a battery to be powered as an electric vehicle. Due to the additional conversion losses and added distribution and support logistics overall efficiency is currently not as good as current ICE ("internal combustion engine") vehicles. Rather it is far simpler and more efficient (by a factor of three to six by some estimates) to transmit locally available sustainable electricity directly into the batteries of a battery electric vehicle.

• alternative fuels are being proposed : alcohol fuel, water (see hydrogen fuel), highly compressed air (see air car), garbage, hemp oil.

• Powering electric vehicles directly from the grid would use the least of any kind of fuel because utilities obtain much higher efficiencies than cars. Vehicles also do not have to carry the weight of the many components between the filler cap and the tip of the exhaust. Electrification of highways and arterials is greatly simplified if vehicles form into trains. These are described in detail at roadtrains.org.

Energy savers

Various technologies have been developed and utilized to increase the energy efficiency of conventional cars or supplement them, resulting in energy savings.

• Regenerative braking

• BMW's Turbosteamer technology to harness the heat generated by conventional internal combustion engines and use it to generate mechanical energy [2], resulting in a 15% increase in fuel efficiency. [3]

• Utilization of waste heat from the engine as useful mechanical energy through exhaust powered steam, stirling engines, thermal diodes, etc..^[1]

• Using Computational Fluid Dynamics in the design stage can produce vehicles which take significantly less energy to push through the air, a major consideration at highway speeds. The Volkswagen 1-litre car and Aptera hybrid car are examples of ultra-low-drag vehicles.

Materials

• Duraluminum, fiberglass, carbon fiber, and carbon nanotubes may totally replace all steel in cars (potentially improving lightness and strength).

Alternatives to the Automobile

Established alternatives for some aspects of automobile use include public transit (buses, trolleybuses, trains, subways, monorails, tramways), cycling, walking, rollerblading and skateboarding.

Car-share arrangements are also increasingly popular – the U.S. market leader has experienced double-digit growth in revenue and membership growth between 2006 and 2007, offering a service that enables urban residents to "share" a vehicle rather than own a car in already congested neighborhoods.^[1] Bike-share systems have been tried in some European cities, including Copenhagen and Amsterdam. Similar programs have been experimented with in a number of U.S. Cities.^[2]

An emerging alternative is personal rapid transit, in which small, automated vehicles would run on special elevated tracks spaced within walking distance throughout a city, and could provide direct service to a chosen station without stops. Another possibility is new forms of personal transport such as segway, which could serve as an alternative to automobiles and bicycles if they prove to be socially accepted.^[3]

All of these alternative modes of transport pollute less than the conventional (petroleum) car and contributes to transport sustainability. They also provide other significant benefits such as reduced traffic-related injuries and fatalities, reduced space requirements, both for parking and driving, reduced resource usage and pollution related to both production and driving, increased social inclusion, increased economic and social equity, and more livable streets and cities. Some alternative modes of transportation, especially cycling, also provide regular, low-impact exercise, tailored to the needs of human bodies. Public transport is also linked to increased exercise, because they are combined in a multi-modal transport chain that includes walking or cycling.

The benefits of possible future car technologies, not yet in widespread use, like zero-emissions vehicles over these alternatives, would be:^[4]

• Increased mobility in rural settings and in some other areas where traffic jams are not severe
• Possibly higher social status
• Overall a better provision for privacy
• Profit for the multinational firms producing cars, and possibly for their employees

References

1. ^ Flexcar Expands to Philadelphia. Green Car Congress (2007-04-02).
2. ^ About Bike Share Programs. Tech Bikes MIT.
3. ^ Jane Holtz Kay (1998). Asphalt Nation: how the automobile took over America, and how we can take it back. ISBN 0520216202. 
4. ^ Transology: M.I.T. Future Car Workshop