During the spring season, winter thaw and heavy vehicles cause roads to deteriorate. Every year, the many state highways impose temporary special weight limits and restrictions during the months of March, April, and May.
These temporary restrictions are known as “frost laws” or “thaw laws”. Frost Law comes into force in the month of March and ends about eight weeks later, depending on weather conditions.
The District authorities identify states that are likely to be affected by frost and will sign and mark the state highways a day before the restrictions are imposed.
Trucks and buses weighing 10,000 pounds or more will be restricted to 30 mph in those areas which are posted for legal weight, or to less than legal weight. In order for road users’ identification, such speed zones are marked using red and yellow markers.
- Red marker = Speed is restricted to 30 mph
- Yellow marker = legal speed can be resumed
Goods exempted from frost or thaw law restrictions
It’s the responsibility of truckers and heavy vehicle operators to comply with frost laws through the end of winter and the beginning of spring. But in some cases, you will be permitted to transport certain goods during frost or thaw months:
- Processed feed (livestock feed that has been rolled, split, ground or is in pellets) delivered to a farm.
- Dead animals for rendering
- Seed potatoes (for export).
- Feed to feedlot (must be transported on B-trains or Tractor and semi-trailer units only).
- Feed to farm (for emergency purposes to provide feed until the pasture is ready), or livestock to pasture.
- Seed grain for cleaning and farm use only.
- Water well drilling equipment to alleviate a water shortage.
- Livestock or grain to market.
Always check with the appropriate permit office to inquire if your shipment is eligible.
State Frost Laws for different US states
Frost laws and seasonal load restrictions ensure that American highways and its users remain safe and unscathed during weather changes. Thanks to advancement in technology, highway authorities now have access to better and reliable data that helps them implement seasonal restrictions and frost laws way ahead. This not only helps them come up with better ways to preserve highway infrastructure and ensure road safety. It is best to always check your state authorities or state transportation website for the latest information.