Because, as we read in the segment of Carniverous Carnival, we see that Olaf was going to Caligari Carnival. To get there, one has to drive along Rarely Ridden Road. So, we see that he didn't want to be disturbed for some reason, or perhaps he didn't want anyone being able to cry for help. Perhaps he knew that the Baudelaire's were in his trunk.
What strikes me as more likely though, is that his personal fortune teller, Madame Lulu told him to do it, knowing the Bauds would come.
After all, according to One of Olaf's cronies, we see that Madame Lulu has helped out Olaf before, and that she was always right.
"...Madame Lulu will know," Olaf said. "With her crystal ball, she'll tell us where the orphans are, where the file is, and anything else we want to know." (TCC Sample)
We know she's been right too, because she has told Olaf where to find the orphans (also in the TCC Sampler).
So, it is probable that Olaf was told by Madame Lulu to have someone chop down all the telephone poles on Rarely Ridden Road, because she knew that Baudelaire's would be coming with them.
It's probably also worth pointing out that Violet herself says that maybe the Bauds would have better luck reaching Mr Poe by phone, a little later on in the segment.
Rick has another reason why:
On TGG pp.72-74, Violet mentions that the Queequeg's telegram device appeared to be working OK, and she speculated that the reason they weren't receiving telegrams must be on the other end of the transmission. Fiona later points out that telegrams travel through telephone lines. So it seems possible, maybe even probable, that Al Funcoot had the lines cut to stop telegram transmissions between members of the other side of the VFD schism, including the Queequeg.
What strikes me as more likely though, is that his personal fortune teller, Madame Lulu told him to do it, knowing the Bauds would come.
After all, according to One of Olaf's cronies, we see that Madame Lulu has helped out Olaf before, and that she was always right.
"...Madame Lulu will know," Olaf said. "With her crystal ball, she'll tell us where the orphans are, where the file is, and anything else we want to know." (TCC Sample)
We know she's been right too, because she has told Olaf where to find the orphans (also in the TCC Sampler).
So, it is probable that Olaf was told by Madame Lulu to have someone chop down all the telephone poles on Rarely Ridden Road, because she knew that Baudelaire's would be coming with them.
It's probably also worth pointing out that Violet herself says that maybe the Bauds would have better luck reaching Mr Poe by phone, a little later on in the segment.
Rick has another reason why:
On TGG pp.72-74, Violet mentions that the Queequeg's telegram device appeared to be working OK, and she speculated that the reason they weren't receiving telegrams must be on the other end of the transmission. Fiona later points out that telegrams travel through telephone lines. So it seems possible, maybe even probable, that Al Funcoot had the lines cut to stop telegram transmissions between members of the other side of the VFD schism, including the Queequeg.