I'll assume that you mean, has ever been observed within our lifetimes, because if you don't limit the statement like that, and leave it open, then we've observed humungous scale changes that have occurred over about 3.5 billion years or even longer. Even with the limit, numerous examples have occurred and been documented extensively within the literature. Often, such findings are publicized in the press. The fact that you personally do not read those articles does not mean they don't exist. Let me draw your attention to this abstract from an article that documents genetic drift in a couple of experimental populations taking place over a period of 15 years.
The rate of genetic drift is largely a function of the generation time. The reason we see so much genetic drift so quickly in bacteria is because they can produce a new generation every 20 minutes. We see it in larger organisms, too--just not as quickly.
There is no possible road. Pointing out something in the middle suggests there might be a path, but it doesn't define the path.
Your desire to not see any road does not equate to the non-existence of a road. Those of us who don't have an emotional attachment to the idea that the creation stories in the book of Genesis are actual literal accounts of real events are busy mapping the roads between A and C, measuring wheel ruts and examining tread marks, and gathering and analyzing the artifacts dropped along the way.
Even very long term studies of bacterial population do not see new species arise, or any particular drift to do so. Given that bacterial generation occur a half million times faster than humans, (20 minutes vs 20 years) we have certainly been studying bacteria long enough to have seen them evolve into a new species. How much DNA change supposedly happened to the human line in 100,000 generations?
Pointing to two different fossils and claiming evolution is not proving it.