Module 1 Geometry
This tells us the job of a roadway in the network and the balance between mobility and access.
What is functional classification?
This is the maximum sustainable service rate under stated conditions.
What is capacity?
For basic freeway segments, LOS is commonly based on this measure of how crowded the freeway is.
What is density?
These traffic signals regulate how vehicles enter the freeway to reduce merge turbulence.
What are ramp meters?
This is the distance a driver needs to see ahead to perceive, react, and stop safely.
What is stopping sight distance?
Under SB 743, California shifted CEQA transportation review away from delay and toward this metric.
What is Vehicle Miles Traveled, or VMT?
These occur where demand exceeds available capacity and queues form upstream.
What are bottlenecks?
This central hub monitors real-time traffic conditions, incidents, and field devices.
What is a Traffic Management Center / Traffic Operations Center?
At intersections and driveways, this clear area helps drivers see approaching traffic.
What is a sight triangle / corner sight distance?
This reminder means a street can operate well for autos but poorly for pedestrians, bikes, or transit.
What is LOS depends on facility type, travel mode, and context?
This freeway section occurs where entering and exiting vehicles cross paths within a limited distance.
What is a weaving section?
This goal focuses on moving more people, not just more vehicles, using HOV, transit, and managed lane strategies.
What is person throughput?
These project inputs drive geometry, including functional class, speed, users, and constraints.
What are design controls?
This manual is the main reference for multimodal capacity and Level of Service analysis.
What is the Highway Capacity Manual, or HCM?
These real-world factors adjust freeway analysis, such as heavy vehicles, narrow lanes, shoulder width, and interchange spacing.
What are adjustment factors?
These lanes prioritize higher-occupancy vehicles or priced users to improve reliability and person throughput.
What are HOV or managed lanes?
This Caltrans guidance supports context-sensitive and Complete Streets design for all users.
What is Caltrans DIB 94?
This California policy shift moved CEQA transportation review away from vehicle delay as the main impact metric.
What is SB 743?
This type of lane can improve freeway operations between closely spaced ramps by supporting merging, diverging, or weaving.
What is an auxiliary lane?
This strategy coordinates freeway, arterial, transit, incident response, and traveler information as one corridor system.
What is Integrated Corridor Management, or ICM?