Kind of a brain dead question. We have much bigger sources of pollution and Asphalt is heavily recycled. We don't have to replace everything that uses oil, just the heaviest offenders.

The green alternative to Asphalt existed before Asphalt in the form of Rail Roads. "Green Asphalt" also exists and is currently used for walking trails and biking trails, though it consists of recycled plastic and rubber, so technically it isn't "asphalt."

The ground up corpses of the recently deceased.

Solar Roadways has been trying to make it work for a while, but I think they will end up being a project better geared for driveways or parking lots or bicycle highways rather than replacing asphalt roads, just based on the enormous amount of issues they've had in the past in trying to shield and protect the lighting elements.

It could still do a lot of good even in the more limited applications, though, so I'm still hoping for their eventual success, even if it ends up being on a smaller scale than what their initial goal was.