????上月初，美國總統奧巴馬提議未來十年撥款20億美元，用來開發新能源汽車和卡車——這個主意對政客們來說一直很有誘惑力。歷屆總統和國會議員為了討好選民，已經砸了不少銀子研究油電混合動力、生物燃料、高級電池、燃料電池、太陽能等各種技術，但迄今為止都沒有取得任何實質性的突破，95%的新車還是在用喝油的引擎。

????現在有了另外一個看來頗有希望的戰略：投資開發自動和半自動駕駛系統。這類技術的主要功能是防止或糾正駕駛者的錯誤。由于能最大限度地減少碰撞，提高行車的安全性，未來的汽車可以設計得更輕，用料更省。汽車企業指出，重量變輕就意味著更省油。輕量化的汽車還能讓電池的電力發揮更大作用，延長續航里程。

????截至目前，汽車廠商還沒有請求政府幫助開發自動駕駛系統（但也沒有拒絕華盛頓當局向它們提供研發補助）。自動駕駛系統這個議題至今還沒有進入政治領域。通用汽車公司（GM）首席技術官喬恩?勞克納表示：“就算自動駕駛技術不能讓汽車駕駛完全自動化，它在減少交通事故上也有很大潛力。”

????勞克納稱，通用汽車旗下的凱迪拉克（Cadillac）將會在2020年前推出一項名為“超級巡航”的功能，使高速公路上行駛的司機不用手握方向盤。汽車會保持在車道中央行駛。如果前方出現車輛，或是有車輛超車到它前面，汽車就會自動減速或停止前進。

????通用表示，用“超級巡航”的駕駛者仍然必須注意路面情況——但他們也能安全地發短信，甚至將目光移開路面。大眾汽車（Volkswagen）的奧迪（Audi）則表示很快會為它的旗艦A8裝備“塞車輔助系統”，它能在低速行駛時保持正常行駛狀態，同時避免撞車。

????可能還得過好幾年——甚至好幾十年，變道警示系統、車車通信、自適應巡航控制、先進視覺和剎車系統才能徹底演進為無人駕駛技術。很多工程師相信，一旦無人駕駛汽車大量上路，由駕駛者導致的事故數量將大幅下降，只有極端情況下才會發生事故。

????勞克納說：“等到我們展示出這項技術的效果時，監管者可能就會考慮調整現行政策，讓汽車企業從根本上改變汽車現有的設計方式，允許我們從汽車上減去大量部件。”

????Earlier this month, President Obama proposed spending $2 billion over the next decade to find an alternative to operating cars and trucks on oil -- an idea that has been catnip to the political class. Previous presidents and congresses have sought favor with voters by spending on gas-electric hybrids, biofuels, advanced batteries, fuel cells, solar, and other technologies. So far, no breakthrough has been made; gas-sipping engines still power more than 95% of new cars.

????There is another promising strategy: investing in autonomous and semi-autonomous systems. Such technology, which prevents or corrects driver error, could minimize collisions, making driving so safe that future vehicles will be built with far less weight and mass than today. Automakers point out that lighter weight automatically translates into less gasoline burned. Lighter vehicles also could make the power of batteries more useful and extend their range.

????Carmakers so far aren't asking for government help to develop autonomous systems. (Assistance from Washington in the form of subsidized research typically isn't refused.) The subject of autonomous systems so far hasn't reached the political arena. "Autonomous related technologies, even if they fall short of making a vehicle fully autonomous, hold the potential to reduce fatalities and injuries on our roadways," says Jon Lauckner, GM's (GM) chief technology officer.

????Lauckner said that GM's Cadillac division will offer a feature called "Super Cruise" before the end of the decade. Super Cruise will allow a driver at highway speeds to take his or her hands off the wheel. The car will remain centered in its lane, and slow down or stop for slower traffic ahead or if a car cuts in front of it.

????A driver using Super Cruise must pay attention to the road, GM says -- but he or she also can safely text or even take eyes off the road. Volkswagen's Audi division said it soon will equip its A8 flagship with "traffic jam assist" that steers and avoids collisions at low speeds on highways.

????It might take years -- or even decades -- for systems like lane-change warning, car-to-car communication, adaptive cruise control, advanced vision and braking to evolve into fully driverless technology. Once driverless cars are used in great number, many engineers believe, accidents that result from driver error will decline sharply, occurring only under extreme or unusual circumstances.

????"When we show this technology can have that effect," Lauckner says. "Regulators might consider adjusting the rules that would allow automakers to fundamentally change the way we design vehicles, allowing a significant amount of mass to be removed from cars."