Which measure typically provides the highest benefit-cost ratio in terms of reducing delay at a signalized intersection?

Updating signal timing and providing coordination at a signalized intersection typically offers the highest benefit-cost ratio for reducing delay. This approach optimizes the existing traffic signal system to improve the flow of traffic by minimizing unnecessary stops and ensuring that vehicles move through the intersection more seamlessly.

When signal timings are adjusted based on current traffic patterns, they can significantly reduce delays, especially during peak traffic hours. Additionally, coordinating signals along a corridor can create a "green wave," where vehicles can progress more smoothly, further diminishing overall delay.

This measure is cost-effective because it often requires minimal physical changes to the intersection infrastructure. Instead, it relies on analytical approaches to maximize the system's performance with existing resources. This contrasts with other options, which may entail more significant expenditures and modifications that do not necessarily yield proportional reductions in delay. For instance, adding turn lanes can help but usually involves construction costs and may only address specific turning movements rather than improving overall signal operation. Modernizing signal control equipment can enhance capabilities, but the initial costs can be high and might not guarantee sufficient improvement in delay reduction without an accompanying review of timing and coordination strategies.