Photo Scavenger Hunts (pick a list, use a random word generator or just browse deviantart/pinterest) 365 Photo Project 52 Weeks Project (choose a theme, shoot it all week) 100 things project - several groups on DA for this that are good, it's not so much on the rest of the web.
Basically, choose something out of your element, and force it into your element, or work with it.
Aimlessly driving around the countryside in order to find interesting nature/landscape subject matter is unlikely to ever yield promising results. I would suggest starting with Google maps, or your knowledge of the local area and find some interesting places to either drive to or walk to. I know you guys have a lot of national parks over there in the States, so why not try with those! Failing that, try checking out local woodland or grasslands. I'm sure there are trails around that you could follow. I've been doing so much of this recently, and I've had some very good success. Luckily, there is lots of woodland, hills and flatland around too, and plenty of rivers. Despite it being winter, I've managed to capture some interesting subject matter. We have a lot of coniferous forest around here as well as deciduous.
If I'm not out in the field taking photos I am scouting new places to drive to and researching constantly. You ought to do the same if you enjoy the sort of photography I do.
I agree with Fuzzypiggy. Driving occupies your mind which is the enemy of finding photographs. Drive to a destination that has possibilities (which is actually almost anywhere). Walk around for a while and look around you, gradually emptying your mind of your normal concerns. Then the photographs will come to you. It is often a good thing to visit the same spots periodically as familiarity with the location will help with the process. Landscape photographers will often frequent the same spot at different seasons, different times of the day with different lighting, and different lenses, and photographed in different ways. They won't all be great, but it all helps with the process of seeing photographs.
Stop driving about! I have experienced the same thing, I'm sure we all have.
I have a patch of marshland about 5 miles from where I live. I've used to go there a lot before I started shooting seriously, just walking around it and I never saw anything of any interest. Last year I had to cut back on the spending and couldn't afford to go miles and miles in the car so I kept going back to the his marshland area. The more times I went back the more things I started to see. I had become used to seeing the same objects over and over which meant that I was now able to see the extraordinary objects as they stood out a lot more. The best thing was that I could drive there in 5 minutes even walk there in about an hour, so I was able to go there before and after work on weekdays and also any time at weekends. I saw the same things in so many different types of outdoor lighting conditions.
In the last 4 years I got maybe 1 or 2 shots from this area, last year I went there at least 20-30 times for 3 months and I must have at least a dozen seriously pleasing keepers. So much so that 2 of the 4 shots of mine that AP magazine published back in November, were from that marshland area! The UK is about to take a blast of Winter weather and so if the roads get snowy and a little dangerous it will be perfect place for me to go shoot without travelling miles at a slow speeds. I can't wait to get back over the marsehs again as I have so many ideas in mind because I know the area inside and out now.
Doing that exercise and having that opportunity taught me so much. Learning to properly scope an area, visualise an area in my mind when planning my landscape shoots and making sure I got out regularly to practice shooting knowing that I hadn't wasted £25 on diesel if I came home empty handed.
just keep looking. I've been photographing my surrounding area for about 5-6 years now, and it wasn't just until last summer than I found a new spot to take pictures of. a park that I had been to countless times, just down the street, that appeared to have "nothing to photograph". Until after having looked at it so many times, I suppose, finally saw it in the way that I could photograph it.
If the big world around you isn't cutting it for you anymore, try getting out of the car, walking around and looking at the details instead of the big picture. Instead of shooting the stream, shoot the crawfish and snapping turtle in the stream.