Hi
Welcome to BYC.
Only you can tell for sure, the rest of us are guessing based on what our property looks like. That said, I live close to a major county highway where people drive around mach 2.3.
The only birds that get to the highway are the guineas. They go down there to rob the brinks trucks for gold and treasure. Guineas are that way. I lose a lot to the road. I have never lost a chicken to the road. I live on a small farm surrounded by Federal wildlife area that does not allow trapping or hunting of predators. I lose some to them. It is not enough to get me to stop free ranging.
The birds really do not go far from the coop. The furthest they go is 300-350 ft towards the other barns, They really stay in the area I have mowed and we live in. There is an unmowed woods right behind the coop they only go 50-100 ft into that.
Good luck on your trial runs. BTW I make mine stay inside until 9-11 am because of birds of prey. Mainly eagles, I have a neighbor across the main road that has a few chickens. I normally wait until I see the BOP take one of his before letting mine out. I figure they (the BOP) have eaten for the day then....