CASS COUNTY SPRING LOAD RESTRICTIONS 

CASS COUNTY HIGHWAY DEPARTMENT SPRING LOAD RESTRICTION POLICY

Under authority of NDCC §39-12-03, local authorities may restrict loads on their highways. The purpose of the load restrictions is to protect the highways from break-up during the spring thaw. Restrictions may be placed at other times during the year to protect highways with weak surfaces from load damage. The following tables list the Cass County Spring Load Restrictions. These restrictions are subject to change as conditions warrant. Actual load restriction postings take precedence over those listed here and are in effect when the load restriction signing is in place. 

It is the Department’s position to not implement Spring Load Restrictions any earlier than necessary. The Department monitors the daily high/low temperatures, which are used to calculate accumulated Freeze and Thaw Indexes. From these indexes, highway engineers can determine when to implement and remove load restrictions.

Be aware that this method is only one decision tool the Department uses to determine when to implement and remove load restrictions. The Department still relies heavily on the existing highway conditions and past experience of its field personnel when making the final decision of when to implement and remove load restrictions.

Implementation and removal of Spring Load Limit Restrictions is highly dependent on weather. It is the Department’s desire to protect its roads while minimizing the period the roads are restricted. The implementation and removal dates for the Spring Load Limit Restrictions are determined based on recommendations from field personnel and the Thaw Index. The Thaw Index is the average daily temperature as compared to a temperature of 29 degrees F. Anytime the average daily temperature exceeds 29 degrees F. we feel we have a thawing day. For example, if a day’s high and low temperatures are 42 degrees F. and 20 degrees F. respectively, then the average temperature for the day is 31 degrees F ((20+42)/2=31). When we compare the day’s average temperature of 31 to the previous referenced 29 we find we have 2 degree days of thawing taking place for that day. We monitor these temperatures daily and accumulate the amount of thawing degree days taking place. When the amount of accumulated thawing degree days approaches 25 to 50 degree days, we feel enough thawing has taken place to warrant implementing the spring load restrictions.

 Click here to view the Cass County Load Restriction Table

Click here to view the Cass County Spring Load Restrictions Map