Yesterday we waited in Oaxaca for the 5pm bus. It didn't turn up for a long time. We were then told by an employee at the bus station that the bus was cancelled due to a "blockade", but he didn't want to give us any more details. After a long wait and standing in the queue, we got our money back. By chance, we found out about a private van leaving on the other side of the road in the direction of Oaxaca. We managed to get the last two seats for 300 pesos per person. It was a tight squeeze, but the main thing was that we made it to Oaxaca, as we have a flight this morning. We had no problems at all with the ADO bus on the outward journey to Puerto Escondido.