Google has been developing autonomous car technology since 2010. Now, it has unveiled the first complete prototype of its self-driving car. The company expects the vehicle to be hitting the streets of California some time in 2015.

An early prototype of the self-driving car was shown off in May this year. In place of manual controls, such as a steering wheel, the car featured mapping systems and sensor technology that allowed it to "see" what was going on around it. There were, however, a number of features yet to be added, such as headlights.

Since then, Google says it has been working with a number of different prototype vehicles, each being used to test the different systems required by an autonomous vehicle. Some of these have included the systems required to recognize road signs and road user gestures that are used on the city streets.

These systems have now all been brought together in a first complete prototype. Although few specifications about the car have been released, it appears to sport a remodeled roof-top sensor module and newly-added indicators and headlights, as well as a lighter gray paint job.

Google says its will continue testing the vehicles with its safety drivers for a "while longer."

Source: Google