I received the following message from the US consulate. In general, they seem to be over-cautious, but if others are not on their email list, you might be interested in this. (at minimum, it may mean traffic disruption and crowds).
The U.S. Embassy in Quito would like to inform U.S. citizens throughout Ecuador that various indigenous and labor groups are planning marches and protests during the week of August 10, 2015, which is Ecuador's Independence Day. Groups from throughout Ecuador are already marching to Quito to join the protests, and are expected to begin arriving in Quito as early as Tuesday, August 12. The main protest activity is scheduled for August 13 in Quito; however, protests may also occur on additional days and in other Ecuadorian cities. Travelers may encounter roads blocked by police or by protesters, and vehicle travel into, out of, and within Quito may be impeded, and it may be advisable to avoid public transportation.
The U.S. Embassy advises U.S. citizens residing in or traveling to Ecuador, particularly Quito, to remain alert and informed via local news sources regarding areas where demonstrations may be occurring and to avoid the areas near the demonstrations. Even demonstrations intended to be peaceful can turn confrontational and escalate into violence. You should avoid areas of demonstrations, and exercise caution if in the vicinity of any large gatherings, protests, or demonstrations. Review your personal security plans; remain aware of your surroundings, including local events; and monitor local news for updates. Maintain a high level of vigilance and take appropriate steps to enhance your personal security and follow instructions of local authorities.