Actually, the reason rattlesnakes have rattles is to warn you away so they don't have to bite you!
Venom takes time to produce, and a snake who bites you and envenomates you has just set itself up to not be able to hunt or defend itself for several days.
In general, rattlesnakes will only bite if startled or abused. If they know you are coming and have an escape route, they'll leave rather than confront you.
When I lived in TN, our place backed on 40K acres of unimproved woodlands belonging to the Fed as part of Ft. Campbell.
There were firebreaks, dirt roads, cut through the woods at intervals, wide enough to be used by armored vehicles. One of those firebreaks was right behind our place and husband and I used to walk it for a ways before turning into the woods. This was a daily ritual when he wasn't deployed or in the field.
There was an approx 5 ft long timber rattler who liked to sun itself on a large, flat rock in the middle of that firebreak.
He'd see us, pick up his head and stare at us, and give a half-hearted rattle. We'd stand very still and wait, well out of strike range.
After expressing his displeasure, the snake would head off into the woods. He never really threatened us and we never really felt frightened of "him"
We even walked around him in the woods once when he was digesting what we assumed was a good sized rabbit based on the size of the bulge in his middle. He was so stuffed and lethargic that he didn't even rattle or pick up his head. husband even poked him with his hiking staff and got a muffled hiss and nothing else.
He was also one of the most beautiful snakes I've ever seen. Beautiful color and markings, and when the autumn leaves fell, he could quit moving and disappear.