Title pretty much says it all. I want to use streeview for an area not on google maps, so could I add my own roads and then add my own panoramic images for streetview?
It's also for personal use, obviously I'm not asking to modify googles actual map.
I'd be happy to use an alternative to streeview too, as long as it does the same thing.
Yes you can:
The Maps Javascript API V3 supports the display of custom panoramas within the StreetViewPanorama object. Using custom panoramas, you can display the interior of buildings, views from scenic locations, or anything from your imagination. You can even link these custom panoramas to Google's existing Street View panoramas.
Source and further Reading: v3 API Services: Providing Custom StreetView Panoramas
You would have to use full wrap-around panoramas like the one below:
Panorama images are generally obtained by taking multiple photos from one position and stitching them together using panorama software. (See Wikipedia's Comparison of photo stitching applications for more information.) Such images should share a single "camera" locus, from which each of the panorama images are taken. The resulting 360 degree panorama can then define a projection on a sphere with the image wrapped to the two-dimensional surface of the sphere.