navigation_safety_core 0.4.2

Pure Dart core models for navigation safety: alert severity, safety score, threshold config, navigation route, and safety scenario identifiers. No Flutter dependency. Consumed by navigation_safety (th [...]

navigation_safety_core

Pure Dart core models for driving-navigation safety.

SafetyScore, AlertSeverity, NavigationRoute, SafetyScenario, NavigationSafetyConfig — the type vocabulary that navigation_safety wraps with Flutter BLoCs and widgets.

This package exists so that non-Flutter consumers — CLI tools, server-side logic, test fixtures, pure-Dart packages like driving_conditions — can depend on the safety vocabulary without inheriting Flutter + flutter_bloc.

If you're building a Flutter app and want the BLoC layer too, depend on navigation_safety instead; it re-exports everything here for back-compatibility.

Scope: driving automation regimes

This package is intended for SAE J3016 Level 0 and Level 1 supportive use — the driver performs the dynamic driving task (DDT) at all times; this package's surfaces (alert severity, alert-density throttle, condition explainer, safety score, road-surface vocabulary) inform the driver but never actuate the vehicle and never close a control loop.

This package does not provide L2+ automation or handover-class supervision. Consumers operating at SAE J3016 Level 2 or above are responsible for adding their own handover-class driver-attention monitoring, take-over-request signalling, and minimum-risk-manoeuvre fallback. Treating this package's advisory output as input to an automation-handover safety contract is out of the documented scope.

Standards-mapping summary (full detail in KNOWN_LIMITATIONS.md):

• ISO 26262: under the current advisory-only framing, this package is product-quality scope, not functional-safety scope. The integrator performs the hazard analysis and decides the final ASIL classification for their integration; the package's wording discipline is consistent with QM at the application layer.
• SAE J3016: L0/L1 supportive. No L2+ claim.
• JIS / JASO (Japanese-domestic automotive standards): not mapped at this scope. Consult a qualified Japanese-domestic functional-safety partner before any IVI-vendor or OEM-pilot integration that targets the Japanese-domestic certification surface.

When this package's alerts are appropriate: informational + density-throttled HMI surfaces over a base map, in a navigation app where the driver retains full control authority and the alert is one of several driver-supervision aids.

When this package's alerts are insufficient: any deployment where alert acknowledgment is part of an automation-handover safety contract, or where loss of an alert frame must be guaranteed-bounded by a functional-safety case rather than by product-quality reliability.

Equal-dignity invariant: alert visibility, severity ordering, and plane-allocation priority in the consuming HMI MUST be severity-driven, never profile-driven. Per-profile differentiation belongs in verbosity, locale, and density-cap surfaces (already provided by AlertExplainer and AlertDensityThrottle); it MUST NOT enter the visibility / preemption path. See KNOWN_LIMITATIONS.md for full discussion.

What's in here

• SafetyScore — composite score across road-surface, visibility, hazard-density, and route-condition axes.
• AlertSeverity — info / warning / critical. Declaration order is load-bearing (callers compare .index to enforce monotonic alert upgrades; lower severity never replaces higher).
• NavigationRoute — typed route representation independent of any specific routing engine.
• SafetyScenario — enumeration of driving-condition scenarios (clear / wet / icy / heavy-snow / etc.) used by the score computation.
• NavigationSafetyConfig — knobs for safety-overlay behavior (alert thresholds, dismissibility, severity caps).

Pure Dart, no native dependencies, no Flutter.

Install

dependencies:
  navigation_safety_core: ^0.1.0

Use

import 'package:navigation_safety_core/navigation_safety_core.dart';

void main() {
  const config = NavigationSafetyConfig();
  final scenario = SafetyScenario.heavySnow;
  final score = SafetyScore.forScenario(scenario, config: config);

  if (score.severity.index >= AlertSeverity.warning.index) {
    print('Alert: ${score.severity.name} — ${score.advisoryMessage}');
  }
}

License

BSD-3-Clause. See LICENSE.