Traffic signal response for autonomous vehicles
Aspects of the disclosure relate to determining whether a vehicle should continue through an intersection. For example, the one or more of the vehicle's computers may identify a time when the traffic signal light will turn from yellow to red. The one or more computers may also estimate a location of a vehicle at the time when the traffic signal light will turn from yellow to red. A starting point of the intersection may be identified. Based on whether the estimated location of the vehicle is at least a threshold distance past the starting point at the time when the traffic signal light will turn from yellow to red, the computers can determine whether the vehicle should continue through the intersection.
1 . A method comprising:
identifying, by one or more processors of a vehicle having an autonomous driving mode, a first time when a state of a traffic signal light associated with a roadway intersection changes from a green light state to a yellow light state;
based on the first time, identifying, by the one or more processors, a second time when the state of the traffic signal light is expected to change from the yellow light state to a red light state;
estimating, by the one or more processors, using a speed characteristic of the vehicle, where the vehicle will be located relative to a threshold location of the roadway intersection when the traffic signal light changes from the yellow light state to the red light state; and
controlling, by the one or more processors, the vehicle to maneuver through the roadway intersection in the autonomous driving mode based on the estimation of where the vehicle will be located relative to the threshold location.
2 . The method of claim 1 , wherein the controlling is further based on whether there are other traffic participants along a trajectory of the vehicle.
3 . The method of claim 1 , further comprising:
determining, by the one or more processors, the threshold location based on characteristics of the roadway intersection.
4 . The method of claim 1 , wherein the identifying of the second time comprises accessing pre-stored information regarding a length of time the traffic signal light will remain yellow.
5 . The method of claim 4 , wherein the pre-stored information regarding the length of time includes a default estimation value.
6 . The method of claim 4 , wherein the pre-stored information regarding the length of time includes a measured value associated with a duration of the yellow light state.
7 . The method of claim 1 , wherein the identifying of the second time comprises receiving information from a remote device about a current status of the traffic signal light.
8 . The method of claim 1 , wherein the identifying of the second time comprises receiving information from a remote device indicating when a status of the traffic signal light changes from the yellow light state to the red light state.
9 . The method of claim 1 , wherein the second time is identified based, at least in part, on a speed limit associated with the roadway intersection.
10 . The method of claim 1 , wherein the threshold location is based on a legal requirement.
11 . The method of claim 10 , wherein the legal requirement is that rear wheels of the vehicle be within the roadway intersection before the traffic signal light changes to the red light state.
12 . The method of claim 1 , wherein controlling the vehicle comprises:
determining, by the one or more processors, whether to continue through the roadway intersection when the traffic signal light is in the yellow light state based on how much braking power would be required to stop the vehicle before reaching the roadway intersection.
13 . A system comprising:
a computing device comprising one or more processors configured to:
operate a vehicle in an autonomous driving mode;
identify a first time when a state of a traffic signal light associated with a roadway intersection changes from a green light state to a yellow light state;
based on the first time, identify a second time when the state of the traffic signal light is expected to change from the yellow light state to a red light state;
estimate, using a speed characteristic of the vehicle, where the vehicle will be located relative to a threshold location of the roadway intersection when the traffic signal light changes from the yellow light state to the red light state; and
control a plurality of systems in the vehicle to operate in the autonomous driving mode based on the estimate of where the vehicle will be located relative to the threshold location.
14 . The system of claim 13 , wherein the control of the plurality of systems is further based on whether there are other traffic participants along a trajectory of the vehicle.
15 . The system of claim 13 , wherein the one or more processors are further configured to access pre-stored information regarding a length of time the traffic signal light will remain yellow, and identify the second time based, at least in part, on the pre-stored information.
16 . The system of claim 15 , wherein the pre-stored information regarding the length of time includes a measured value associated with a duration of the yellow light state.
17 . The system of claim 13 , wherein the one or more processors are further configured to receive information from a remote device about a current status of the traffic signal light, and identify the second time based, at least in part, on the received information.
18 . The system of claim 13 , wherein the one or more processors are further configured to receive information from a remote device indicating when a status of the traffic signal light changes, and identify the second time based, at least in part, on the received information.
19 . The system of claim 13 , wherein the threshold location is based on a legal requirement.
20 . The system of claim 13 , further comprising the vehicle.