Traffic signal systems for communicating with vehicle sensors

A method of communicating traffic signal information to a vehicle, the method comprising:

• receiving, by at least one controller, returns of a radar signal from at least one spatially-encoded marker of a traffic signal apparatus, wherein the at least one spatially-encoded marker comprises a movable element;
• determining a message based on a detected movement of the movable element based on the returns;
• and
• controlling the vehicle based on the message, wherein the message describes a traffic directive given by the traffic signal apparatus.

A system comprising:

• a traffic signal apparatus for controlling traffic at an intersection, the traffic signal apparatus having at least a first light source, a second light source, and a third light source, the traffic signal apparatus having at least one spatially-encoded marker;
• and
• a vehicle having at least one controller and a radar,
• the radar configured to transmit a radar signal and receive returns of the radar signal from the at least one spatially-encoded marker,
• the at least one spatially-encoded marker comprises a movable element and an actuator coupled to the movable element, wherein the actuator is configured to move the movable element,
• the at least one controller configured to determine a message based on movement of the movable element based on the returns and to control the vehicle based on the message, wherein the message describes a traffic directive given by the traffic signal apparatus.