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Roman Kotenko
Roman Kotenko

Posted on • Originally published at road511.com

Spring Load Limits API for Trucking Compliance

Every spring, northern states and provinces impose weight restrictions on roads as frost leaves the ground. The pavement is weakest during thaw, and unrestricted heavy loads cause millions in damage.

The problem: every state publishes restrictions differently, with different dates, formats, and geographic references. Fleet operators check each state manually.

Road511 normalizes spring load limits from MN, WI, MI, ON, QC, and NS into one API with polyline geometry and active date ranges.

The Data

curl "https://api.road511.com/api/v1/features?type=weight_restrictions&jurisdiction=MN" \
  -H "X-API-Key: your_key"
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{
  "data": [
    {
      "id": "mn-wr-zone3-seg12",
      "jurisdiction": "MN",
      "feature_type": "weight_restrictions",
      "name": "CSAH 5 - Frost Zone 3",
      "start_time": "2026-03-10T00:00:00Z",
      "end_time": "2026-05-15T00:00:00Z",
      "properties": {
        "restriction_type": "seasonal_weight",
        "weight_limit_tons": 5,
        "frost_zone": "Zone 3",
        "from_location": "TH 10",
        "to_location": "CSAH 12"
      }
    }
  ]
}
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Each restriction has:

  • Polyline geometry — the exact road segment, not just a point
  • Start/end dates — when the restriction is active
  • Weight limit — in tons (MN), as a percentage reduction (MI), or by road class (WI)
  • Location description — from/to landmarks

Coverage

State/Province Type Details
Minnesota Spring load limits ~26 segments with ton limits by frost zone
Wisconsin Class II + Posted 148 restricted highways + 19 posted roads
Michigan Truck Operator Route Map ~1,757 segments with 25-35% weight reductions
Ontario Spring load limits 143 polyline segments
Quebec Trucking network restrictions Province-wide route restrictions
Nova Scotia Spring weight restrictions 8,599 restricted segments

Corridor Check

Use the truck corridor endpoint to check if a planned route crosses any active restrictions:

curl "https://api.road511.com/api/v1/truck/corridor?from_lat=44.98&from_lng=-93.27&to_lat=46.87&to_lng=-96.77&buffer_km=10&weight=30" \
  -H "X-API-Key: your_key"
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Minneapolis to Fargo — returns every weight restriction along the corridor that your 30-ton load would violate.

Historical Tracking

Road511 tracks when restrictions are posted and lifted via feature_history. Over multiple seasons, this data shows:

  • When each state typically starts/ends restrictions
  • Which zones get restricted first (geographic progression of thaw)
  • Year-over-year pattern changes

Try It

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