Transit street design elements are an investment—often the dense, constrained downtown and urban centers where transit has the highest potential ridership are also the places with the slowest and least predictable traffic speeds.
In these contexts, where congestion is high and private parking is limited, transit has the greatest potential to efficiently move more people through fixed right-of-way. Allocating on-street transit facilities can boost reliability, travel speed, capacity, and modal balance, increasing the total performance of the street.
Transit lanes and transitways must communicate to all users how street width is allocated in time and space. Transit lanes delineate space within the roadbed as exclusive, either full- or part-time, and can generate transit benefits with relatively low implementation costs. Transitways physically separate a portion of the street for transit’s exclusive use, providing high-quality running way at all times.