Colectivos connect the city's barrios and greater Buenos Aires. You're assured a seat on a diferencial bus (indicated by a sign on the front); they run less frequently than colectivos and are more expensive. Stops are every other block (200 meters [656 feet apart) and are marked by small, easy-to-miss metal signs citing number of the bus line. Buses, which are generally safe, run 24 hours a day, although service is less frequent at night.
Hail your bus and let the driver know your destination; then insert your coins in the machine (exact change isn't necessary, but coins are), which will print your ticket. Fares are 80¢ within the city, 1.25 to 1.65 pesos outside the city; diferencials cost 2 pesos. There are no daily or weekly discount passes.
Once on board, head for the back, which is where you exit. A small bell on the grab bar lets you signal for a stop. Don't depend on drivers for much assistance; they're busy navigating traffic. You can purchase a Guia T, an essential guide to the routes, at any news kiosk, or visit the Spanish-language colectivo Web site for info.
Colectivo (www.loscolectivos.com.ar).
