Wikipedia
A pesero is a form of public transport, most commonly seen in Mexico City. Its name derives from the fact that in the beginning of this form of transport a flat fee of one peso was charged per ride (hence the name "pesero" which could be interpreted as "peso collector").
First seen in the 1970s as the so-called taxi colectivo ( share taxi or collective cab), peseros were originally big cars with fixed routes which would pick passengers at any point through their route, and drop them off also at any point. Passenger capacities were limited to those of a large car (usually up to six people plus a driver).
Being both cheaper than a proper taxi and able to cover routes not feasible for larger buses or other forms of public transport, by the 1980s, pesero owners started using Volkswagen Microbus vehicles (known in Mexico as combis from its Kombinationskraftwagen variant) for increased capacity of up to 12 passengers. The inability of the government-run public transport to serve the public's needs in a high-growth environment caused high demand and made them a very good business. Pesero owners kept up with demand by adding more units and routes, particularly in newly developing parts of the city such as Nezahualcóyotl, and they did so without any centralized planning. By the mid-to-late 1980s, most peseros were converted to gasoline powered, half-length passenger buses (known as microbús or simply el micro in Mexico, but they are not similar to the VW Microbus vehicles mentioned before). There were capable of carrying around 22 sitting people or up to 50 if standing people are counted
To this day, a fleet of approximately 28,000 peseros (as of 2007) carry an important part of Mexico City's public transport passengers, surpassing by far the capacity of the Mexico City Metro, STE trolleybuses, buses and taxis; peseros, (including VW Microbus, micros proper and full-length diesel buses) carry up to 60% of the city's passengers. However, despite the success of the decentralized system in carrying large numbers of passengers for low cost, the government is seeking ways to regulate microbus operation, ostensibly to address problems such as a lack of operator training and documented unit maintenance. Proposed changes include reducing the number of units or replacing them with full-size diesel powered buses which carry more passengers per unit, and can utilize transfers and/or a unified farecard system, such as the system that has been implemented in León, Guanajuato ( Optibus). Other proposed alternatives include expanding the Metro and STE trolleybus network and different forms of transportation, such as the Metrobús, which has completely replaced pesero travel along Avenida de los Insurgentes avenue, and the Tren Suburbano, which will serve areas north of the city. Unlike most other North American and European cities of similar size, it is not possible to buy a pass or farecard in Mexico City that is valid on all types of transport within the city, rather, each form of transport one boards requires an additional (but low, the Metro fare is only MXN 5 pesos) fare.
Pesero drivers do not receive a fixed salary but are required to meet a daily quota prescribed by the owner of the vehicle. The driver is then allowed to keep the rest of fares of the day. This fosters fierce competition among drivers, as every passenger is seen as valuable merchandise towards meeting the quota and thus increasing the driver's personal profit. As a result, often, two or three battered down peseros race furiously against one another with complete disregard for the passengers they carry or for other vehicles. Accidents, often deadly, ensue and are fairly common. However, the lack of any real alternative keep them in high demand throughout the city.
Currently peseros travel fixed routes, being able to pick up or drop off passengers anywhere through the route (a major source of traffic problems and annoyance for the sudden and unexpected stops). The fees are according to distance traveled: from MXN $4.00 for a trip of up to 5 km, MXN $4.50 for a 5-to-12 km trip, and MXN $5.50 for a trip of 12 km or more. Routes usually begin in metro stations and end in outlying neighborhoods of the city or sometimes even in municipalities in Mexico State.
Typically, less than $5.00 MXN routes begin in a small metro station that serves only one line, but the number rapidly increases depending on the number of metro lines going through a station. The terminal station of a metro line usually functions as a transport hub and may be served by tens of different pesero routes. In addition, every major avenue in the city is served by at least one pesero route.
The lack of organization of the pesero network, there is no comprehensive map of routes available to the general public. Nevertheless, routes each have a route number in order to distinguish them from each other in license plates. Individual peseros also have a sign affixed to the windshield indicating major points covered by the route such as metro stations (denoted by the Metro logo), hospitals, schools, avenues, etc.