{
  "title": "The Pre-Trip Brief",
  "author": "Charles",
  "standard": "FMVSS-393",
  "route_profile": {
    "designation": "I-15 Northbound",
    "segment": "Barstow to San Bernardino",
    "conditions": {
      "light": "Dawn",
      "ambient_temp_f": 42,
      "dew_point_status": "rising"
    },
    "rig_spec": {
      "make_model": "Freightliner Cascadia",
      "engine": "Detroit DD15",
      "transmission": "Eaton Fuller 18-speed"
    }
  },
  "air_brake_system": {
    "air_build_rate_max_sec": 45,
    "target_pressure_psi": 85,
    "governor_cut_out_range_psi": [120, 125],
    "low_air_warning_activation_psi": [55, 75],
    "foot_valve_leakage_max_psi_min": 3,
    "parking_brake_release_threshold_psi": 60,
    "critical_failure_mode": "Air loss exceeding 3 psi/min during foot valve test"
  },
  "tire_rim_assembly": {
    "drive_tire_tread_min_inches": 0.125,
    "steer_tire_tread_min_inches": 0.1875,
    "rim_clamp_bolt_torque_ft_lbs": 140,
    "torque_tolerance_percent": 5,
    "reject_variance_percent": 10,
    "bead_seat_pit_depth_max_in": 0.005,
    "physics_note": "Torque variance >10% creates stress concentrator; fatigue crack propagation accelerates exponentially"
  },
  "lighting_signaling": [
    {
      "component": "Headlamp (low)",
      "luminous_intensity_cd": 500,
      "color_temp_k": [2800, 3200],
      "alignment_vertical_deg": 0.5,
      "alignment_horizontal_deg": 1
    },
    {
      "component": "Brake lamp",
      "luminous_intensity_cd": 425,
      "filter": "Red passband"
    },
    {
      "component": "Turn signal",
      "luminous_intensity_cd": 200,
      "flash_rate_cpm": [60, 120]
    },
    {
      "component": "Side marker",
      "luminous_intensity_cd": 50,
      "visibility_angle_deg": 80
    }
  ],
  "powertrain_diagnostics": {
    "def_quality_min_percent": 32.5,
    "def_low_alarm_percent": 15,
    "injector_pulse_width_deviation_max_percent": 2,
    "egr_stroke_time_ms": 180,
    "oil_pressure_idle_min_psi": 25,
    "oil_pressure_cruise_psi": [45, 65],
    "shutdown_protocol_threshold_psi": 20
  },
  "sources": [
    {
      "label": "NHTSA FMVSS Standard No. 393",
      "url": "https://www.nhtsa.gov/laws-and-regulations/federal-motor-vehicle-safety-standards/fmvss-standard-no-393"
    }
  ]
}