Lane

The geometry of lanes are described by AbstractLane objects, as a parametrized center line curve, providing a local coordinate system.

Conversions between the (longi, lat) coordinates in the Frenet frame and the global \(x,y\) coordinates are ensured by the position() and local_coordinates() methods.

The main implementations are:

API

class highway_env.road.lane.AbstractLane[source]

A lane on the road, described by its central curve.

metaclass__

alias of ABCMeta

abstract position(longitudinal: float, lateral: float) → ndarray[source]

Convert local lane coordinates to a world position.

Parameters:

  • longitudinal – longitudinal lane coordinate [m]

  • lateral – lateral lane coordinate [m]

Returns:

the corresponding world position [m]

abstract local_coordinates(position: ndarray) → tuple[float, float][source]

Convert a world position to local lane coordinates.

Parameters:

position – a world position [m]

Returns:

the (longitudinal, lateral) lane coordinates [m]

abstract heading_at(longitudinal: float) → float[source]

Get the lane heading at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane heading [rad]

abstract width_at(longitudinal: float) → float[source]

Get the lane width at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane width [m]

classmethod from_config(config: dict)[source]

Create lane instance from config

Parameters:

config – json dict with lane parameters

abstract to_config() → dict[source]

Write lane parameters to dict which can be serialized to json

Returns:

dict of lane parameters

on_lane(position: ndarray, longitudinal: float | None = None, lateral: float | None = None, margin: float = 0) → bool[source]

Whether a given world position is on the lane.

Parameters:

  • position – a world position [m]

  • longitudinal – (optional) the corresponding longitudinal lane coordinate, if known [m]

  • lateral – (optional) the corresponding lateral lane coordinate, if known [m]

  • margin – (optional) a supplementary margin around the lane width

Returns:

is the position on the lane?

is_reachable_from(position: ndarray) → bool[source]

Whether the lane is reachable from a given world position

Parameters:

position – the world position [m]

Returns:

is the lane reachable?

distance(position: ndarray)[source]

Compute the L1 distance [m] from a position to the lane.

distance_with_heading(position: np.ndarray, heading: float | None, heading_weight: float = 1.0)[source]

Compute a weighted distance in position and heading to the lane.

local_angle(heading: float, long_offset: float)[source]

Compute non-normalised angle of heading to the lane.

class highway_env.road.lane.LineType[source]

A lane side line type.

class highway_env.road.lane.StraightLane(start: ndarray | Sequence[float], end: ndarray | Sequence[float], width: float = AbstractLane.DEFAULT_WIDTH, line_types: tuple[LineType, LineType] | None = None, forbidden: bool = False, speed_limit: float = 20, priority: int = 0)[source]

A lane going in straight line.

New straight lane.

Parameters:

  • start – the lane starting position [m]

  • end – the lane ending position [m]

  • width – the lane width [m]

  • line_types – the type of lines on both sides of the lane

  • forbidden – is changing to this lane forbidden

  • priority – priority level of the lane, for determining who has right of way

position(longitudinal: float, lateral: float) → ndarray[source]

Convert local lane coordinates to a world position.

Parameters:

  • longitudinal – longitudinal lane coordinate [m]

  • lateral – lateral lane coordinate [m]

Returns:

the corresponding world position [m]

heading_at(longitudinal: float) → float[source]

Get the lane heading at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane heading [rad]

width_at(longitudinal: float) → float[source]

Get the lane width at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane width [m]

local_coordinates(position: ndarray) → tuple[float, float][source]

Convert a world position to local lane coordinates.

Parameters:

position – a world position [m]

Returns:

the (longitudinal, lateral) lane coordinates [m]

classmethod from_config(config: dict)[source]

Create lane instance from config

Parameters:

config – json dict with lane parameters

to_config() → dict[source]

Write lane parameters to dict which can be serialized to json

Returns:

dict of lane parameters

class highway_env.road.lane.SineLane(start: ndarray | Sequence[float], end: ndarray | Sequence[float], amplitude: float, pulsation: float, phase: float, width: float = StraightLane.DEFAULT_WIDTH, line_types: list[LineType] | None = None, forbidden: bool = False, speed_limit: float = 20, priority: int = 0)[source]

A sinusoidal lane.

New sinusoidal lane.

Parameters:

  • start – the lane starting position [m]

  • end – the lane ending position [m]

  • amplitude – the lane oscillation amplitude [m]

  • pulsation – the lane pulsation [rad/m]

  • phase – the lane initial phase [rad]

position(longitudinal: float, lateral: float) → ndarray[source]

Convert local lane coordinates to a world position.

Parameters:

  • longitudinal – longitudinal lane coordinate [m]

  • lateral – lateral lane coordinate [m]

Returns:

the corresponding world position [m]

heading_at(longitudinal: float) → float[source]

Get the lane heading at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane heading [rad]

local_coordinates(position: ndarray) → tuple[float, float][source]

Convert a world position to local lane coordinates.

Parameters:

position – a world position [m]

Returns:

the (longitudinal, lateral) lane coordinates [m]

classmethod from_config(config: dict)[source]

Create lane instance from config

Parameters:

config – json dict with lane parameters

to_config() → dict[source]

Write lane parameters to dict which can be serialized to json

Returns:

dict of lane parameters

class highway_env.road.lane.CircularLane(center: ndarray | Sequence[float], radius: float, start_phase: float, end_phase: float, clockwise: bool = True, width: float = AbstractLane.DEFAULT_WIDTH, line_types: list[LineType] | None = None, forbidden: bool = False, speed_limit: float = 20, priority: int = 0)[source]

A lane going in circle arc.

position(longitudinal: float, lateral: float) → ndarray[source]

Convert local lane coordinates to a world position.

Parameters:

  • longitudinal – longitudinal lane coordinate [m]

  • lateral – lateral lane coordinate [m]

Returns:

the corresponding world position [m]

heading_at(longitudinal: float) → float[source]

Get the lane heading at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane heading [rad]

width_at(longitudinal: float) → float[source]

Get the lane width at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane width [m]

local_coordinates(position: ndarray) → tuple[float, float][source]

Convert a world position to local lane coordinates.

Parameters:

position – a world position [m]

Returns:

the (longitudinal, lateral) lane coordinates [m]

classmethod from_config(config: dict)[source]

Create lane instance from config

Parameters:

config – json dict with lane parameters

to_config() → dict[source]

Write lane parameters to dict which can be serialized to json

Returns:

dict of lane parameters

class highway_env.road.lane.PolyLaneFixedWidth(lane_points: list[tuple[float, float]], width: float = AbstractLane.DEFAULT_WIDTH, line_types: tuple[LineType, LineType] | None = None, forbidden: bool = False, speed_limit: float = 20, priority: int = 0)[source]

A fixed-width lane defined by a set of points and approximated with a 2D Hermite polynomial.

position(longitudinal: float, lateral: float) → ndarray[source]

Convert local lane coordinates to a world position.

Parameters:

  • longitudinal – longitudinal lane coordinate [m]

  • lateral – lateral lane coordinate [m]

Returns:

the corresponding world position [m]

local_coordinates(position: ndarray) → tuple[float, float][source]

Convert a world position to local lane coordinates.

Parameters:

position – a world position [m]

Returns:

the (longitudinal, lateral) lane coordinates [m]

heading_at(longitudinal: float) → float[source]

Get the lane heading at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane heading [rad]

width_at(longitudinal: float) → float[source]

Get the lane width at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane width [m]

classmethod from_config(config: dict)[source]

Create lane instance from config

Parameters:

config – json dict with lane parameters

to_config() → dict[source]

Write lane parameters to dict which can be serialized to json

Returns:

dict of lane parameters

class highway_env.road.lane.PolyLane(lane_points: list[tuple[float, float]], left_boundary_points: list[tuple[float, float]], right_boundary_points: list[tuple[float, float]], line_types: tuple[LineType, LineType] | None = None, forbidden: bool = False, speed_limit: float = 20, priority: int = 0)[source]

A lane defined by a set of points and approximated with a 2D Hermite polynomial.

width_at(longitudinal: float) → float[source]

Get the lane width at a given longitudinal lane coordinate.

Parameters:

longitudinal – longitudinal lane coordinate [m]

Returns:

the lane width [m]

to_config() → dict[source]

Write lane parameters to dict which can be serialized to json

Returns:

dict of lane parameters