14 billion kilometers

This is the distance traversed by Voyager-1 from our sun in 20 years, therefore enters the final boundaries of our solar system. It went through "termination shock", a kind of enveloppe made of gas and stellar dust that quickly slows down solar wind (electrically charged gas that goes 300-700 km/s), as it begins to mix with interstallar winds.

This had to be said. Read a tiny excerpt from Nasa website:

"To envision the Sun's presence in the Milky Way galaxy, think of a ship plowing through the ocean, being tossed by currents. As the ship sails ahead, a bow shock spreads around the vessel.

The area under the Sun's influence, stretching well beyond the planets and forming what's called the heliosphere, is like a ship. The outer edges of the heliosphere are gently buffeted by interstellar wind, the gas and dust between the stars. As the Sun orbits the center of the Milky Way galaxy, the heliosphere moves as well, creating a bow shock ahead of it in interstellar space."

Voyager-1 longevity has gone far beyond its original expectations, and is now schedulded to transmit information until 2020. Where will it be at this time?

Wired related article
Nasa page - What's It Like Where Voyager Is? (excellent explanations)