Operational costs of running a BRT system are generally lower than light rail, though the exact comparison varies, and labor costs depend heavily on the wages which vary between countries. For the same level of ridership and demand, higher labor costs in the developed world relative to developing countries will tend to encourage developed world transit operators to prefer operate services with larger but less frequent vehicles. This will allow the service to achieve the same capacity while minimizing the number of drivers. This may come as a hidden cost to passengers in lower demand routes who experience a significantly lower frequencies and longer waiting times. In the developing world the operating cost advantages of BRT over light rail or streetcar are much greater due to lower wages. In the study done by the GAO, BRT systems usually had lower costs based on "operating cost per vehicle hour", "operating cost per revenue mile", and "operating cost per passenger trip", mainly because of lower vehicle cost and lower infrastructure cost. The initial capital costs of diesel BRT are also much less lower than a trolleybus system.