I've ridden collectivo type vans in a number of latin america countries (Philippines has same although sometimes in form of jeepnee), they work quite well, you shout 'para' or some such where you need to stop and wave boldly when you need to get on. Much prefer it to a bus, and also since they are privately owned it is very easy to kick assholes off which is one of my biggest gripes with dealing with public transit.