bus rapid transit

Bus rapid transit is a high-capacity public transport system built around standard or articulated buses operating on fixed routes with dedicated infrastructure. Unlike ordinary bus services that share road space with general traffic, BRT systems use segregated lanes, traffic signal priority, and level-boarding platforms to deliver transit speeds and reliability approaching light rail, but at a fraction of the capital cost.

The core infrastructure includes off-street bus lanes separated from traffic by physical barriers, medians, or paint; level platforms at stations that align with bus doors to enable fast boarding; and active traffic signal control that extends green lights when buses approach. Most systems operate vehicles 40 to 60 feet long, often articulated models carrying 80 to 160 passengers. Stations are typically spaced 400 to 800 metres apart, designed to handle rapid fare collection either pre-boarding or on-vehicle.

BRT variants exist along a spectrum. Basic systems use painted lanes on existing streets with minimal station upgrades. Mature systems in cities like Bogotá, Istanbul, and Jakarta invest in fully separated right-of-way, climate-controlled stations, and closed-door boarding through integrated ticketing. Some hybrid schemes operate in mixed traffic during peak demand to maximize flexibility, reverting to dedicated lanes during off-peak hours.

Why BRT versus other rapid transit?

A metro system typically costs USD 500 million to USD 2 billion per 10 kilometres; a light rail line costs USD 100 million to USD 500 million per 10 kilometres. BRT costs range from USD 10 million to USD 100 million per 10 kilometres, depending on station complexity and right-of-way acquisition. The trade-off is passenger capacity: BRT rarely exceeds 15,000 passengers per hour per direction in peak conditions, while rail systems handle 40,000 or more. This makes BRT suited to cities with moderate density corridors and limited transit budgets.

Common failures in BRT implementation include allowing general traffic to encroach on dedicated lanes, creating bottlenecks at intersections, and underestimating demand growth without capacity to add vehicles. Systems that separate payment from boarding, enforce lane discipline strictly, and coordinate signal timing with vehicle flow avoid the worst congestion. Conversely, bus lanes treated as suggestions or filled with parked vehicles revert to ordinary bus service with added frustration.

BRT terminology reflects its hybrid identity: practitioners call the dedicated route the busway or transit mall; the platform-level boarding zones are level-boarding stations or stations; and the physical separation is the running way or right-of-way. The concept emerged in the 1970s and gained momentum in Latin America, where capital constraints and land availability favoured bus-based solutions over rail. It remains primarily a fixture of developing and middle-income cities; wealthy cities tend toward rail once congestion justifies the cost.