Anyone who has watched Terminator, Stealth, or Short Circuit can tell you that it will only be a matter of time before a bolt of lightning or downed power line lends contagious self-awareness to these robo-cars... and then our cars will all lock the doors, turn on the heaters, and cart us off into the desert to bake us to death. But assuming that engineers devise an effective anti-murder system, there are many advantages to a car that needs no driver.
The most obvious benefit is that a person who is not occupied with driving is free to do something else, such as sleep, read, make phone calls, watch the news, or bake up a batch of pipin' hot soy-protein choc-alike cupcakes in the car's moto-bake. Life in the future is good. But that's small potatoes, the tip of the iceberg. The self-driving automobile of the future will also dramatically reduce air pollution (even if it still runs on fossil fuels), cut any transit time to a fraction of the length it is now, and remove gobs and gobs of unpleasantness from the world.
The peer-to-peer Internet applications of today are paving the way for the secure network of decentralized, information-sharing cars of tomorrow. Each car will wirelessly convey messages to those around it, relaying hazard reports, road construction, weather, and any number of other useful tidbits. Roadside nodes will also receive, store, and convey these data to any passing cars which were out of reach of the message when it originated. Clearly precautions will need to be taken to prevent car-borne software viruses, such as keeping the guidance software on a read-only memory chip; and the system will need to come with a large grain of virtual salt pre-installed, to be taken with all incoming data.
Once perfected, vehicles which are not operated by mistake-prone bags of intelligent meat will safely cruise well over 100 miles per hour in non-residential areas, with powerplants that are optimized to maintain such high speeds efficiently. And they'll traverse the entire distance non-stop, because intersections will no longer constipate the flow of traffic on thoroughfares. Instead, a scheduling node at each intersection will assign every approaching vehicle a tiny slice of time that it may pass through safely, and each car will automatically slow or accelerate slightly in order to meet that schedule. Vehicles will criss-cross through the intersection at high speeds, every one with its very own guaranteed, unhindered fraction of a second. This will not only save time, but also benefit the environment... cars that don't have to slow to a stop and then re-accelerate consume much less fuel, and consequently cause less pollution.
Another time-saving advantage is that every lane of a highway will become dynamic. If more traffic is moving one direction than another, the roadside traffic-governing nodes will switch the travel direction of one or more lanes to average out the traffic flow, providing maximum efficiency at all times. The intelligent cars will smoothly shuffle into the new lane configuration without missing a beat. In the event that a higher-speed emergency vehicle passes through, an entire lane can be allocated to its passage, speeding its progress greatly.
Naturally, many households won't even own a robo-car, instead relying on pay-per-use automated taxis that can be wirelessly summoned to one's location at a few moments' notice. And while private taxis will be available, one can save money by riding a shared taxi, whose route is constantly adjusted to pick up new passengers near it's dynamic path as it drops others off at their destinations; all with the straightforward simplicity of an elevator's "come get me" button. The prevalence of these shared vehicles will further reduce air pollution and congestion.
But taxi services won't be the only businesses benefiting from robo-cars. Shipping companies will gain a huge boost in efficiency: Freight will find its way to its destination in about 25% of the time it currently takes by truck. Autonomous cargo vehicles will cross great distances at high speeds, shipping their goods nationwide, non-stop. Automated trucks will also consume much less fuel and have no need for a driver, which will decrease shipping costs. And retail businesses will have a new outlet: Upon request, rolling vending machines can come right to your door to dispense food, clothing, tactile-holographic mega-porn, or anything else you can think of... all for a small added fee of course.
For too long, humankind has wasted precious hours guiding our clunky, inefficient machines of transport from points A to points B. The transition period may prove messy as hardware-driven cars share the road with their meatware-driven counterparts... but there is much to gain in environmental benefits, time-saving benefits, and convenience. A few may dig their heels in and hold out against the steady march of progress, but envy is a great human motivator. One can only watch so many cars full of news-watching, soy-cupcake-enjoying commuters whiz by in the ROBOCARS ONLY lane before giving in to the inevitable.