Rear driver tire smoking after stop and go traffic

Sorry, you're probably working on it now.
Agreed, unlikely the rubber smell is actually tire. Plus you'd probably have heard a big POP by the time you posted.
Stop n go traffic isn't really the right condition to toast brakes or tires. Less stress going slow. My money is on a stick caliper and you smell brake pads cooking.

I'd be impatient and cool that sucker down with some water.