197. Speed Limit Violation

The speed_limit_violation_checker verifies whether the Ego complies with the applicable speed limits during the simulation. It continuously compares the vehicle's current speed with the active road speed limit and detects any violations based on both the speed limit and the violation_factor_threshold.

197.0.1 Start condition

The interval begins when:

• The Ego's speed exceeds the violation_speed_threshold and persists for the duration specified by debounce_start_time.
• The corresponding speed_limit_watcher interval is active.

The violation_speed_threshold is evaluated as: violation_speed_threshold = speed_limit × violation_factor_threshold, where speed_limit is the current applicable speed limit and violation_factor_threshold is a configurable float parameter.

197.0.2 End condition

The interval ends when:

• The Ego's speed falls below the threshold: violation_speed_threshold − violation_speed_threshold_tolerance, where violation_speed_threshold is the speed level that triggered the interval and violation_speed_threshold_tolerance is a configurable parameter defining how far below this threshold the Ego must drop to return to compliance.
• The associated speed_limit_watcher interval ends.

197.1 Plot

The figure below illustrates the speed limit violation. One violation is detected. The blue area indicates where the speed limit violation occurred.

197.2 Attributes

The following attributes define the behavior and characteristics of the evaluator.

197.3 Configuration parameters

The following parameters can be configured to customize the evaluator's behavior.

197.4 Metrics

The following metrics are recorded and tracked by the evaluator.

197.5 Log and Error Messages

197.6 Usage

197.6.1 How to instantiate

The speed_limit_violation_checker is built into the Ego only, as part of the sut_vehicle.speed_limit modifier. The modifier includes two components: speed_limit_watcher and speed_limit_violation_checker.

extend sut_vehicle.speed_limit:
    checker speed_limit_violation_checker(speed_limit_violation_data) is while_w(is_speed_limit_violation) with:
        it.sut_issue(...)

The checker is active only when all of the following conditions are met:

• ego_speed_limit_violation_checker_config.enabled and ego_speed_limit_watcher_config.enabled are both set to true
• speed_limit_watcher has an active interval
• The Ego speed exceeds speed_limit × violation_factor_threshold for at least debounce_start_time

197.6.2 Set parameters at instantiation time

Use ftlx_global_eval_config.ego_speed_limit_violation_checker_config defaults unless overridden below.

197.6.3 Define and use a custom parameter set

To customize the checker for all scenarios, configure speed_limit_violation_checker_config. Default values are defined in ftlx_global_eval_config. Create a config instance:

const custom_speed_limit_violation_config: speed_limit_violation_checker_config = new
set custom_speed_limit_violation_config.violation_factor_threshold = 1.15
set custom_speed_limit_violation_config.violation_speed_threshold_tolerance = 3kph
set custom_speed_limit_violation_config.debounce_start_time = 0.5s
set custom_speed_limit_violation_config.issue_severity = error
set custom_speed_limit_violation_config.enabled = true

extend ftlx_global_eval_config:
    set ego_speed_limit_violation_checker_config.violation_factor_threshold = \
        custom_speed_limit_violation_config.violation_factor_threshold
    set ego_speed_limit_violation_checker_config.violation_speed_threshold_tolerance = \
        custom_speed_limit_violation_config.violation_speed_threshold_tolerance
    set ego_speed_limit_violation_checker_config.debounce_start_time = \
        custom_speed_limit_violation_config.debounce_start_time
    set ego_speed_limit_violation_checker_config.issue_severity = \
        custom_speed_limit_violation_config.issue_severity

Customize per scenario To override fields for a specific scenario, extend the modifier directly. The fields are bound to the config by default:

extend sut_vehicle.speed_limit:
    keep(debounce_start_time == 1.0s)
    keep(violation_speed_threshold_tolerance == 3kph)

197.6.4 Disabling the checker

To disable the checker globally, set enabled to false in the config:

extend ftlx_global_eval_config:
    set ego_speed_limit_violation_checker_config.enabled = false

extend sut_vehicle.speed_limit:
    on @start:
        override(speed_limit_violation_checker, run_mode: freeze)

197.7 Additional information

All parameters are required, but you don't need to customize all of them. For any parameter you don't customize with set, the default value defined in speed_limit_violation_checker_config is used. Disabling the violation checker also requires an active speed_limit_watcher; freeze that watcher if speed-limit tracking is not needed.