Is melting of Tar for road construction a reversible change?

In India roads are made up of a black liquid which is prepared by melting a black material(probably coal tar). After cooling the liquid becomes very rigid. Can this solid be converted back to its previous liquid state by heating?

P.S: This is a question in my book. I think that after getting solidified the chemical composition of Tar may change so it can't be converted back to its original state.

• Chip off a little piece and try heating it. Chemistry is an experimental science. I think it would melt just fine. – Ivan Neretin Sep 29 '15 at 7:53
• @IvanNeretin I don't have proper apparatus. Heating Tar on a cooking stove would be very risky, I guess. – user31782 Sep 29 '15 at 8:32
• On extremely hot days I have observed this tar melt slightly. Whether it changes to the original material, I do not know. – Shailesh Sep 29 '15 at 9:02
• If you've even seen a roof being tarred the tar is solid which is melted and then applied to the roof. – MaxW Mar 26 '16 at 19:00

The process is reversible, and can actually happen to some extent in hot weather, see here or here. It can definitely soften on a hot day, and it melts at $150\rm~^\circ C$.