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Which states cut axle and gross weight during the spring thaw, what each one publishes, when we last read it, and a direct link to the state's own bulletin. A load that is legal on a road in July can be illegal on the same road in March.
We never tell you a road is clear. Restrictions are posted road by road and lift with a few days' notice, so we publish what each state's own document says, the date we read it, and the link. Where a state publishes only a map or a PDF we say so rather than inventing a limit from it, and where our copy is old we say how old and which way that errs.
12 states whose DOT posts and lifts restrictions on the roads it maintains. Each is polled on its own cadence, derived from that state's published season — a statute where one exists, otherwise its own bulletin history.
NDDOT publishes every restricted segment as GeoJSON with the order number, its effective time and the ton limit. This is the one state where we hold segment-level detail.
Six frost zones, each with a published start and end date. MnDOT announces changes at least three days ahead, which is what makes a several-hour poll comfortably fast enough.
Restrictions apply to routes marked "Seasonal" on the MDOT Truck Operators Map — a 25% axle-weight reduction on rigid pavement and 35% on flexible. Which pavement a given mile is, is a property of the road, not of the state, so we never compute the reduction ourselves.
Washington is one of the 21 states this engine already prices permits for, so a restriction here can change a quote we issue. The feed is a typed JSON API and carries a start and end date per restriction.
Zone-based Class II restrictions of 6 tons single / 10 tons tandem, 24 tons gross. Announced by zone, and the same page also carries the frozen-road law, which moves in the opposite direction.
SDDOT sets and lifts restrictions from accumulated freeze/thaw indices and field observation, and announces each change by press release and on this page.
Published through the statewide travel-information map rather than as a bulletin, so we link to it and watch it for change rather than claiming a parsed limit.
Maine calls these posted roads rather than frost laws. The list covers state and state-aid highways and is republished as roads are added and released.
Break-up restrictions are issued regionally by DOT&PF. The season is later and longer than any lower-48 state, which is why this row has its own window rather than sharing the northern-tier default.
Alaska DOT&PF — Measurement Standards & Commercial Vehicle Compliance
Idaho publishes restrictions through the 511 traveller map. There is no bulletin document to cite, so we watch the page and link to it.
Restrictions are announced through the NDOT truck-permit pages rather than as a numbered bulletin series.
Published on the statewide road-conditions map. Wyoming restricts fewer miles than its neighbours because much of the state system is built on free-draining base.
These are routinely listed as "frost law states", and for most of them that is true of the county roads and false of the state system. Knowing which it is decides who you have to call.
ODOT does not impose spring weight restrictions on the state highway system. Ohio frost laws are posted by county engineers and township trustees on local roads, road by road, with no statewide list. Check the county engineer for the specific local roads on your route.
INDOT does not seasonally restrict the state highway system. Indiana frost laws are posted by county highway departments on county roads.
IDOT does not post spring weight restrictions on state highways. Illinois seasonal limits are set by county and township highway commissioners on local roads.
MoDOT runs no annual spring thaw programme. Missouri restrictions are local and episodic; MoDOT publishes any exceptional embargo on its motor-carrier notices page, which is the page linked here.
NYSDOT does not seasonally restrict the touring routes. New York frost laws are posted by towns and counties on local roads, typically for a few weeks in March and April.
Pennsylvania regulates weak roads through YEAR-ROUND posting and bonding, not through a spring thaw season. A posted-and-bonded road is restricted in July as well as in March, so it is a routing question rather than a seasonal one.
CDOT runs no spring thaw weight programme. Colorado closes and chain-controls mountain routes in winter, which is a traction and closure question, not an axle-weight one.
No spring thaw weight programme. New Jersey does not reach the sustained frost depth the northern tier restricts for.
No spring thaw weight programme on the state system.
The oversize & overweight permit calculator prices single-trip state permit fees for 21 states and raises a cited warning on any leg crossing a state with a restriction in force. It does not reprice the permit for a restriction, and the reason is on that warning: the restriction applies to specific roads, and a quote priced from state codes does not know the route.
