Legal weights and tonnage

1. Office of Motor Vehicle Enforcement
Iowa Department of Transportation
Agriculture Outreach

2. This slide module is intended to summarize commercial Vehicle rules
and regulations and is not intended to be used for legal guidance or as
a substitute for applicable local, state, and federal statutes.
While every attempt has been made to ensure the completeness and
accuracy of the information contained in this presentation, it is not a
detailed explanation of all applicable local, state and federal statutes.
The module is part of a larger presentation and as such is only part of a
summary of regulations that may or may not apply to you.
By use of this resource, the user agrees the Iowa Department of
Transportation assumes no liability or responsibility for the user’s
understanding and compliance to the rules and regulations
DISCLAIMER

3. Legal Weights and Tonnage

4. What can trucks legally weigh?
More axles = More weight
More length = More weight
Up to the tires’ safe load ratings
and/or statutory maximum weight
limits for single, tandem, group and
gross axles
Vehicle weight

5. Tandems, groups and gross
Axles 1-5 = Five-axle gross
1 2 3 4
Vehicle weight
Axles 2-5 = Four-axle group
Axles 2-3=Tandem

6. Single axle - 20,000 lbs
Vehicle weight

7. Tandem axle - 34,000 lbs
Vehicle weight
Obtain exact
measurements
on tandems
40” - 96”

8. Singles Within A Tandem
Vehicle weight
34,000
20,000
14,000

9. Singles Within A Tandem
Vehicle weight
12,000
22,000
34,000

10. Singles Within A Tandem
Vehicle weight
18,000
19,000
37,000

11. Single axels within a spread
20,000 lbs
20,000 lbs
10’ spread/40,000 lbs
Vehicle weight

12. All six- and seven-axle vehicles
that are long enough can gross
up to 96,000 lbs.
No interstate travel allowed.
Vehicle weight

13. Bridge weight limits
All trucks, including livestock and
construction vehicles legally
weighing more than 80,000 lbs,
must comply with
posted weight
limits on bridges
and highway
structures.
Vehicle weight

14.  Iowa law allows for a tolerance on
the registered weight or tonnage
 5 percent for all processed products
 25 percent for all raw ag-products
The license weight tolerance does
not mean a truck can be overloaded.
License tonnage tolerance