configuration. If an outbound dedicated bus lane can be accommodated, both bus lanes could be moved to the center of the bridge.
INTERSECTIONS AND SIGNALS The intersections along the BRT corridor determine how efficiently the buses and pedestrians can access the stations while there is also a perceived impact on general traffic. An important step in the BRT corridor planning will be optimizing the intersection performance by designing the intersection configuration and adjusting the traffic signal timing. Each intersection along the BRT corridor will need to be optimized individually based on the characteristics of that site. The intersections should be designed to achieve the following:61 1 Safe and convenient crossings for pedestrians; 2 Minimal delay for BRT buses; 3 Minimal delay for mixed traffic. The intersections along the BRT corridor need to be designed to operate as efficiently as possible for all road users. This is an iterative process. It should start with data collection about the existing flow of people and vehicles. By removing travel lanes, the BRT corridor may exacerbate existing bottlenecks along the corridor, which will need to be resolved. The proposed service frequency combined with the configuration of the lanes and signal timing along the corridor may also cause bottlenecks in the bus lanes, which will need to be identified and mitigated. Several techniques can be used to rationalize the intersections on the corridor.
COLLECT TRAFFIC COUNTS AND DETERMINE INTERSECTION DELAY Data about the existing traffic conditions in the corridor needs to be collected and analyzed to inform design of the BRT corridor intersections. Traffic volume data and turning movements will be needed for each intersection along the BRT corridor. ITDP contracted a consultant to collect some traffic count data for lower Broadway intersections in January 2020. It will be critical to understand where all of the existing bottlenecks and pinch points are and how they may be affected by the addition of BRT lanes and potential removal of general traffic lanes. Next, the impact of the existing traffic signal phasing on the BRT lanes needs to be examined to see if the signal delay will make the busway congested. Each intersection must be analyzed to understand its impact on the BRT corridor and the general traffic. Any intersection that introduces significant delay should be redesigned to improve the overall efficiency for all road users. This will be an iterative process, incorporating some of the subsequent steps. 58
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For a more extensive discussion about how to approach intersection design along the BRT corridor, see Section 24.2 of the BRT Planning Guide (ITDP 2021).
