There are multiple motivations for self driving cars.
- Self driving cars have the potential to be much safer.
Self driving cars are far more reliable than humans and can learn and have their software improved and upgraded, resulting in safer roads and far fewer accidents.
More on self-driving car safety: http://bigthink.com/ideafeed/googles-self-driving-car-is-ridiculously-safe
- Self driving cars can lead to greater road efficiency.
Traffic jams and obstructions occur due to inefficiencies in human driving, see this MIT simulation of a "phantom traffic jam": https://www.youtube.com/watch?v=Q78Kb4uLAdA and self driving cars can be programmed to avoid this.
- Greater economic and environmental benefit
Self driving cars can keep driving costs down by conserving fuel and hence lead to a better environmental impact.
More on fuel efficiency: http://movimentogroup.com/blog/how-self-driving-cars-increase-fuel-efficiency-decrease-waste/
- Ease of transport
Self driving cars make transport easier and mean that drivers may be unnecessary in the future, resulting in a more pleasurable and easier drive.
In addition, this would make it easier for people with disabilities to travel as well as simplify the travel experience. Children could potentially be driven to school by a car without the supervision of a parent, for instance.
- Parking
Self driving cars can be called to pick you up, meaning the need for parking in nearby locations and/or long walks to find your car may become a thing of the past as your car would drive up to you to pick you up.
- Things we haven't even thought of yet :)