Which road safety countermeasure has the least impact on operations and accessibility?

• A. Widening freeways to add capacity.
• B. The installation of rectangular rapid flashing beacons (RRFBs) to enhance pedestrian visibility at crosswalks.
• C. Implementing tolling on arterial streets.
• D. Building roundabouts at every intersection.

Answer: (B)

The question focuses on finding a safety measure that improves protection for road users while causing the smallest disruption to how the road network operates and how people access it. Rectangular rapid flashing beacons at crosswalks fit this best because they enhance pedestrian visibility and alert drivers to crossing pedestrians without changing the road’s geometry, capacity, or traffic patterns. They’re installed at existing crossings with relatively minor work and don’t require widening lanes, building new ramps, or altering how intersections function. That keeps overall operations and accessibility largely unchanged, while still delivering a notable safety benefit for pedestrians. By contrast, widening freeways involves large-scale construction and land use changes that disrupt operations and access; tolling arterial streets can shift travel behavior and reduce accessibility for some users; and roundabouts change intersection geometry and flow, which can affect both vehicle and pedestrian movements and require more space and adjustment.