A PA-28 pilot; attempting to make up time on a long cross country by flying direct VMC routes vice on an IFR flight plan; discovered he had penetrated a restricted area.

Narrative

I was on a long cross country trip. I just landed at a nearby airport to refuel. I was in the clouds for the last 2 HRS on an IFR flight plan. I had traveled almost 80 NM extra as opposed to flying a direct route. I wanted to make my next leg of the trip VFR and a direct route. The clouds were low at approximately 2;500-3;000 FT. I was flying VFR when I noticed on my GPS screen that I was coming up on some air space that I just assumed was the outline of the Class E airspace when the Class D airport (WAL) was closed. After looking at the sectional I realized that it was not Class E I was in but rather restricted airspace. The cloud bases were low and my main concentration was to avoid the clouds and Class D airspace near by. I was unfamiliar with the area and did not realize until it was too late but I had inadvertently entered restricted airspace 6604A & 6604B in northern Virginia. I left the area as soon as I realized my mistake. I was not in radio contact with any facility at the time. I learned that you must study your route of flight thoroughly and maybe making up for lost time is not always the best way of doing things.