24Intersections and Signal Control

A bland smile is like a green light at an intersection, it feels good when you get one, but you forget it the moment you’re past it.Douglas Coupland, novelist, 1961–

The objective of this chapter is to equip the reader with tested practical knowledge to design and evaluate the layout and operation of intersections along BRT corridors. Intersections can cause significant delays in BRT operations, particularly by hindering station access, and they are the points where the BRT project has the largest perceived impact on mixed traffic and walking.

An important strategy to improve the performance of intersections to better accommodate public transport, pedestrians, and other vehicles is to restrict general-traffic turning movements at intersections. The BRT Standard awards up to 7 points for good handling of BRT movements through intersections, with the most points given to systems that prohibit all turns across the busway.

Turns prohibited across the busway7
Signal priority at intersections2
No intersection treatments0

This chapter also discusses the placement of stations relative to intersections along the corridor and the treatment of public transport vehicle turning movements, which are desirable to have but can also harm an intersection’s performance. Other elements of intersection treatments that are discussed include: signal prioritization technology for public transport vehicles, priority in roundabouts, narrow sections with mixed traffic, and techniques for keeping pedestrians and cyclists safe.

Definitions that pervade the whole chapter are laid out in the first section; the second section covers the general approach to intersection problem solving; and the subsequent sections discuss different tools to improve intersection efficiency, particularly when grade separation is available.

Contributors: John Jones, HHO Africa; Karl Fjellstrom, Far East BRT; Annie Weinstock, BRT Planning International; Elkin Bello, consultant; Ulises Navarro, ITDP Latin America; Carlos Pardo, Despacio; Pedro Szász, consultant; Arthur Szász, Protocubo