1.2.3: Determine Ramp State

This process shall implement the selected traffic control strategies on some or all of the entry ramps in the network served by the Manage Traffic function. It shall implement the strategies only using the ramps that are specified in the implementation request and shall coordinate its actions with those of the process that controls the road network. The process shall base its ramp metering decisions on the data from sensors and ramp meters monitoring traffic conditions upstream and downstream of the ramps. Data from sensors on the ramp used to detect flow past the meter, extent of queues on the ramp, and the presence of vehicles will also be used as the basis for the ramp metering decisions. The decision making process shall use an algorithm to determine the ramp's state based on the ramp control strategy and the sensor input data received. The process shall coordinate its activities with the process responsible for controlling the road (surface street) network.

This process is associated with the Traffic Management Center physical object.

This process is associated with the following functional objects:

• TMC Dynamic Lane Management and Shoulder Use
• TMC Multi-Modal Coordination
• TMC Traffic Metering

This process is associated with the following data flows:

• current_ramp_state
• transit_ramp_overall_priority
• roadway_info_traffic_metering_data
• traffic_metering_data_for_signage
• coordination_data_ramps_to_roads
• coordination_data_roads_to_ramps
• ramp_data
• ramp_signal_state
• selected_ramp_control_strategy
• static_data_for_ramps
• transit_ramp_priority_given
• ramp_meter_data_collection_configuration
• m_and_c_ramp_priority_request
• m_and_c_ramp_priority_given