Route 15 was stripped for repaving

There is no cost-effective way to proceed, even if you had a claim (see below). The problem is, you will have to sue in the state in which the stretch of road was located, because that is the only state with a connection to the claim and so which has courts which can exercise jurisdiction (or power) over the case. If you don't hire an attorney, you will potentially have to make multiple trips to that state; and while if you hire a local lawyer, he or she can do some of the appearances for you, 1) you'll be paying a lawyer (which money you can't get from the other side), and 2) you'll have to make one appearance, at the trial, at a minimum.  Furthermore, you'd likely need to hire an expert witness, too: someone like a highway engineer or safety expert who can testify that the way the road was stripped was too dangerous (e.g. too deep a drop off, too many potholes, etc.) and/or that there wasn't proper signing or other warning of what was happening, so as to not give you sufficient opportunity to slow or avoid the worst of it--and such experts do not work cheap. Your non-expert opinion on these subjects will most likely not be accepted by the court.
You can, of course, call the highway department in the other state, try to submit a claim to them, see if they or their insurer will voluntarily pay you something--but if they don't, you'll have to sue, as per the above. And if you sue, you could easily spend more than you would get back (even if you won) on the case.
And you can't assume 100% that you will win: if the highway was stripped, marked, warning signs posted, etc. in a "reasonable" fashion--which basically means the standard way such repairs are done--then the other side did nothing wrong; as long as they adhere to accepted practice, they are not liable.