Where can you find the capacity of base (perfect) conditions for traffic?

• A. HCM - Exhibit 12-4
• B. Traffic Volume Survey Reports
• C. National Traffic Safety Administration Publications
• D. Highway Capacity Manual - Section 3.5

Answer: (A)

The capacity of base (perfect) conditions for traffic is found in the Highway Capacity Manual (HCM), specifically referenced in Exhibit 12-4. This exhibit presents a detailed breakdown of the various capacity values for different geometric and operational conditions of roads and lanes under ideal circumstances.

The Highway Capacity Manual is a comprehensive guide that provides methodologies for analyzing traffic flow and capacity across various types of roadways and intersections. Exhibit 12-4 specifically offers the necessary metrics to evaluate traffic capacity, allowing engineers and planners to make informed decisions regarding roadway design and expected traffic performance.

Other resources, such as Traffic Volume Survey Reports, typically focus on the actual observed volumes and patterns of traffic usage rather than idealized conditions. Similarly, the National Traffic Safety Administration Publications mainly cover safety statistics and guidelines but do not specifically address traffic capacity under perfect conditions. While Section 3.5 of the Highway Capacity Manual could also contain relevant information, it does not direct you to the specific capacity values presented in Exhibit 12-4, making this exhibit the most precise and authoritative source for understanding base traffic capacity.