Tools for Transit Priority

Transit Priority can be achieved through a wide variety of physical and non-physical measures, such as dedicated transit lanes spanning entire corridors or just a few critical blocks, localized measures such as queue-jumps and modal filters, or area-wide measures to curb background traffic, such as Limited Traffic Areas and Congestion Pricing. Transit-dedicated lanes can be placed in different positions within the roadway, with associated benefits and limitations regarding conflict management, encroachment risks, deployment costs, and urban design. Effective transit priority can result not only from the intrinsic characteristics of a transit lane type, for example, the relative position from the conflict-prone curb space, but also from how they interact with the broader urban environment and traffic flows as part of a broader strategy to foster transit priority

How to navigate the toolbox

The transit priority tools are grouped into three main categories. Each category is subdivided into classes, and each class may be further organized into a few sub-typologies. The terminology is partially based on NACTO’s classification, as illustrated in the “Transit Street Design Guide,” and has been further refined and expanded to better account for international practices. For each typology, the toolbox provides a brief overview of its main characteristics, history, and key facts.

Linear Continuous Measures (dedicated lanes)

This category encompasses the most continuous transit-priority physical arrangements, namely dedicated transit lanes. The organization into seven main classes is based on two major factors: i) the relative position of the dedicated transit lane with respect to the curb and the other components of the right-of-way (general traffic lanes, parking, etc.); ii) the likely presence of curbside activity, making a distinction between limited-access roadways, such as highways with no sidewalks or property access, and urban streets with mixed traffic, curbside activity and vehicular property access. Each main class clusters similar typologies based on the dedicated lane's relative position within the roadway. The sub-typologies are based on the urban context and specific applications.

Localized Measures

This category includes transit-priority measures that are localized rather than linear and typically target points of delay, such as intersections and stops, as well as strategies to reduce “transit signal delay,” i.e. delays caused by waiting at red traffic lights, a set of measures broadly defined as transit signal priority (TSP).

Area-wide measures

This category includes measures that cover large areas through access permitting, pricing, or other broad traffic management measures. While these measures don’t specifically target transit priority, they do improve transit performance by reducing background traffic and lowering private-vehicle demand in the targeted area.