We live on a sometimes busy state route, with a large auto parts plant, and school down the road. Also we have more than double summer traffic due to the lake area nearby. We got guineas last year to help with the high number of insects we deal with every year. We brooded chicks, keets and poults in our garage, just 200ft from the road. The guinea keets were kept there for 6 weeks.
All our fowl were then moved to our barn, 300ft from the road. The guineas were kept enclosed in the barn for 2 weeks to help them recognize home. After that they were let out through a pop door to an enclosed run. Of course being guineas in no time they were flying over the fence, and as said above, are still unable to figure how to reverse the process. We were diligent to herd them to the back yard each time they came to the front of the house. Now they may walk through the front, but only to get from one side of the house to the other. So far our guineas stay on our property. They do not go near or to the road.
We have 5 pearl guineas who move over our 2+ acres several times a day. We are surrounded by fields that are planted each year by the owner - no residence in sight.
All our fowl were allowed out during the winter, except for ice and high winds. Our guineas are the first out and the last in nearly every day. Yes, they love wooded areas, both trees and ground. They do have predators that can take them if they do not have access to a coop for night when they are most vulnerable. They share an unheated barn with the chickens and turkeys. (water was heated to keep from freezing.)
Our turkeys have escaped to visit workers at the plant several times and we have to watch them much closer than the guineas. The turkeys seek humans, the guineas just yell at them and run them off.
If you have the time to train them and get them used to their surroundings it is possible, even close to the road. I recommend day old keets, not grown birds, as they imprint on their first surroundings. Adult guineas must be penned up for at least 6 weeks to keep them from trying to find their previous home.