Bus rapid transit is a system of fixed-route public transportation
used in urban areas. Unlike standard local bus routes, bus rapid transit (BRT) routes are optimized for faster service in areas with heavy traffic congestion
. Some of the methods of improving service include operating buses on separate roadways or reserved bus lanes, realigning stops to provide faster express and local service, using access-controlled stations for fare collection instead of an onboard farebox
, and traffic light
preemption systems. BRT systems generally have an average speed greater than that of local bus routes, but slower than that of passenger rail systems.
BRT routes may incorporate separate roadways, often referred to as 'busways', or dedicated lanes on an expressway, to avoid congested local traffic. The South Dade Busway, operated by Miami-Dade Transit, connects the existing Metrorail system to areas in the southern end of the county using a separate roadway reserved for use for buses and emergency vehicles. The separate roadway used for this BRT system ensures that even the slowest of rush hour traffic cannot cause delays on the bus routes. The city of Adelaide, Australia uses a special bus guideway called the O'Bahn, which is equipped with steel guides to keep a bus centered on two concrete running rails via pilot rollers on the chassis. On this dedicated guideway, the buses can be operated at speeds of up to 100 km/h.
BRT does not necessarily require separate roadways. Some systems, such as the Orlando Lynx Lymmo, provide service to downtown stops on dedicated bus lanes. Traffic signals along the Lymmo route are equipped with automatic preemption patterns to ensure the buses are not delayed by red lights. The downtown Lymmo service thus has priority over other traffic present on the streets. Additionally, highway service can be implemented using special dedicated High Occupancy Vehicle and bus lanes on expressways.
One of the advantages of separate roadways and dedicated expressway lanes for BRT use is that special stations can be used in place of roadside bus stops. These stations can have fare control systems such as turnstiles in place as a replacement for onboard fare collection, which can be a major bottleneck in the boarding and unloading of passengers. The elimination of onboard fare collection greatly reduces the time spent at each stop.
How fast does a bus rapid transit system operate? This varies greatly based on many variables, including the number of stops, whether or not the bus is operating on public roads, and how fare collection is handled. I've personally observed the average speed of the local bus routes in Miami-Dade County to be roughly 11 miles per hour at off-peak hours and 6 miles per hour (ouch!) during rush hour conditions. Buses on the South Dade Busway seem to average about 15 miles per hour independent of the time of day. This may not really be all that rapid, but it's a lot nicer than an average of six miles per hour. I generally consider this to be a successful system.